Release 1.23.1

Fix warnings transfer between workers and master node with pytest >= 3.8

.github/PULL_REQUEST_TEMPLATE.md

@@ -13,5 +13,3 @@ Here's a quick checklist that should be present in PRs:
     ```
     Fix issue with non-ascii contents in doctest text files.
     ```
-
-

.gitignore

@@ -30,5 +30,6 @@ issue/
 pytestdebug.log
 .tox/
 .cache/
+.pytest_cache/
 .eggs/
 .idea/

.pre-commit-config.yaml

@@ -0,0 +1,24 @@
+repos:
+-   repo: https://github.com/ambv/black
+    rev: 18.6b4
+    hooks:
+    -   id: black
+        args: [--safe, --quiet]
+        language_version: python3.6
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v1.3.0
+    hooks:
+    -   id: trailing-whitespace
+    -   id: end-of-file-fixer
+    -   id: check-yaml
+    -   id: debug-statements
+    -   id: flake8
+-   repo: local
+    hooks:
+    -   id: rst
+        name: rst
+        entry: rst-lint --encoding utf-8
+        files: ^(CHANGELOG.rst|HOWTORELEASE.rst|README.rst|changelog/.*)$
+        language: python
+        additional_dependencies: [pygments, restructuredtext_lint]
+        python_version: python3.6

.travis.yml

@@ -21,12 +21,24 @@ env:
 - TOXENV=py-pytest31
 - TOXENV=py-pytest32
 - TOXENV=py-pytest33
+- TOXENV=py-pytest36
+- TOXENV=py-pytest38
 
 install: pip install tox setuptools_scm
 script: tox
 
+stages:
+- linting
+- test
+- name: deploy
+  if: repo = pytest-dev/pytest-xdist AND tag IS present
+
 jobs:
   include:
+    - stage: linting
+      python: '3.6'
+      script:
+      - tox -e linting
     - stage: test
     # python x env above are already included into this stage
     - python: "2.7"
@@ -37,10 +49,6 @@ jobs:
       env: TOXENV=py36-pytestmaster
     - python: "3.6"
       env: TOXENV=py36-pytestfeatures
-    - python: "3.6"
-      env: TOXENV=flakes
-    - python: "3.6"
-      env: TOXENV=readme
 
     - stage: deploy
       python: '3.6'
@@ -50,7 +58,7 @@ jobs:
       deploy:
         provider: pypi
         user: ronny
-        distributions: sdist bdist_wheel  
+        distributions: sdist bdist_wheel
         skip_upload_docs: true
         password:
           secure: 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

CHANGELOG.rst

@@ -1,3 +1,73 @@
+pytest-xdist 1.23.1 (2018-09-25)
+================================
+
+Bug Fixes
+---------
+
+- `#341 <https://github.com/pytest-dev/pytest-xdist/issues/341>`_: Fix warnings transfer between workers and master node with pytest >= 3.8.
+
+
+pytest-xdist 1.23.0 (2018-08-23)
+================================
+
+Features
+--------
+
+- `#330 <https://github.com/pytest-dev/pytest-xdist/issues/330>`_: Improve collection performance by reducing the number of events sent to ``master`` node.
+
+
+pytest-xdist 1.22.5 (2018-07-27)
+================================
+
+Bug Fixes
+---------
+
+- `#321 <https://github.com/pytest-dev/pytest-xdist/issues/321>`_: Revert change that dropped support for ``pytest<3.4`` and require ``six``.
+
+  This change caused problems in some installations, and was a mistaken
+  in the first place as we should not change version requirements
+  in bug-fix releases unless they fix an actual bug.
+
+
+pytest-xdist 1.22.4 (2018-07-27)
+================================
+
+Bug Fixes
+---------
+
+- `#305 <https://github.com/pytest-dev/pytest-xdist/issues/305>`_: Remove last references to obsolete ``py.code``.
+
+  Remove some unnecessary references to ``py.builtin``.
+
+- `#316 <https://github.com/pytest-dev/pytest-xdist/issues/316>`_: Workaround cpu detection on Travis CI.
+
+
+pytest-xdist 1.22.3 (2018-07-23)
+================================
+
+Bug Fixes
+---------
+
+- Fix issue of virtualized or containerized environments not reporting the number of CPUs correctly. (`#9 <https://github.com/pytest-dev/pytest-xdist/issues/9>`_)
+
+
+Trivial Changes
+---------------
+
+- Make all classes subclass from ``object`` and fix ``super()`` call in ``LoadFileScheduling``; (`#297 <https://github.com/pytest-dev/pytest-xdist/issues/297>`_)
+
+
+pytest-xdist 1.22.2 (2018-02-26)
+================================
+
+Bug Fixes
+---------
+
+- Add backward compatibility for ``slaveoutput`` attribute to
+  ``WorkerController`` instances. (`#285
+  <https://github.com/pytest-dev/pytest-xdist/issues/285>`_)
+
+
 pytest-xdist 1.22.1 (2018-02-19)
 ================================
 

HOWTORELEASE.rst

@@ -24,13 +24,13 @@ To publish a new release ``X.Y.Z``, the steps are as follows:
 
 #. Create a new branch named ``release-X.Y.Z`` from the latest ``master``.
 
-#. Install ``pytest-xdist`` and dev requirements in a virtualenv::
+#. Install ``tox`` in a virtualenv::
 
-    $ pip install -e . -U -r dev-requirements.txt
+    $ pip install tox
 
-#. Update ``CHANGELOG.rst`` file by running::
+#. Update the necessary files with::
 
-    $ towncrier --version X.Y.Z --yes
+    $ tox -e release -- X.Y.Z
 
 #. Commit and push the branch for review.
 

ISSUES.txt

@@ -19,7 +19,7 @@ tag: feature
 
 allow to run xdist own tests using its own mechanism.
 currently this doesn't work because the remote side
-has no py.test plugin.   How to configure/do
+has no pytest plugin.   How to configure/do
 register "xdist.plugin" on the remote side?
 
 see to avoid any "from _pytest" internal imports

LICENSE

@@ -5,10 +5,10 @@
   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   copies of the Software, and to permit persons to whom the Software is
   furnished to do so, subject to the following conditions:
-     
+
   The above copyright notice and this permission notice shall be included in all
   copies or substantial portions of the Software.
- 
+
   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -16,4 +16,3 @@
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   SOFTWARE.
-

OVERVIEW.md

@@ -1,78 +1,76 @@
 # Overview #
 
 `xdist` works by spawning one or more **workers**, which are controlled
-by the **master**. Each **worker** is responsible for performing 
+by the **master**. Each **worker** is responsible for performing
 a full test collection and afterwards running tests as dictated by the **master**.
 
 The execution flow is:
 
 1. **master** spawns one or more **workers** at the beginning of
-   the test session. The communication between **master** and **worker** nodes makes use of 
+   the test session. The communication between **master** and **worker** nodes makes use of
    [execnet](http://codespeak.net/execnet/) and its [gateways](http://codespeak.net/execnet/basics.html#gateways-bootstrapping-python-interpreters).
    The actual interpreters executing the code for the **workers** might
-   be remote or local. 
-  
+   be remote or local.
+
 1. Each **worker** itself is a mini pytest runner. **workers** at this
-   point perform a full test collection, sending back the collected 
+   point perform a full test collection, sending back the collected
    test-ids back to the **master** which does not
    perform any collection itself.
-     
+
 1. The **master** receives the result of the collection from all nodes.
    At this point the **master** performs some sanity check to ensure that
    all **workers** collected the same tests (including order), bailing out otherwise.
    If all is well, it converts the list of test-ids into a list of simple
    indexes, where each index corresponds to the position of that test in the
-   original collection list. This works because all nodes have the same 
+   original collection list. This works because all nodes have the same
    collection list, and saves bandwidth because the **master** can now tell
    one of the workers to just *execute test index 3* index of passing the
    full test id.
-   
+
 1. If **dist-mode** is **each**: the **master** just sends the full list
    of test indexes to each node at this moment.
-   
+
 1. If **dist-mode** is **load**: the **master** takes around 25% of the
    tests and sends them one by one to each **worker** in a round robin
    fashion. The rest of the tests will be distributed later as **workers**
    finish tests (see below).
 
 1. Note that `pytest_xdist_make_scheduler` hook can be used to implement custom tests distribution logic.
-   
+
 1. **workers** re-implement `pytest_runtestloop`: pytest's default implementation
    basically loops over all collected items in the `session` object and executes
-   the `pytest_runtest_protocol` for each test item, but in xdist **workers** sit idly 
+   the `pytest_runtest_protocol` for each test item, but in xdist **workers** sit idly
    waiting for **master** to send tests for execution. As tests are
-   received by **workers**, `pytest_runtest_protocol` is executed for each test. 
-   Here it worth noting an implementation detail: **workers** always must keep at 
-   least one test item on their queue due to how the `pytest_runtest_protocol(item, nextitem)` 
-   hook is defined: in order to pass the `nextitem` to the hook, the worker must wait for more 
-   instructions from master before executing that remaining test. If it receives more tests, 
-   then it can safely call `pytest_runtest_protocol` because it knows what the `nextitem` parameter will be. 
-   If it receives a "shutdown" signal, then it can execute the hook passing `nextitem` as `None`. 
-   
+   received by **workers**, `pytest_runtest_protocol` is executed for each test.
+   Here it worth noting an implementation detail: **workers** always must keep at
+   least one test item on their queue due to how the `pytest_runtest_protocol(item, nextitem)`
+   hook is defined: in order to pass the `nextitem` to the hook, the worker must wait for more
+   instructions from master before executing that remaining test. If it receives more tests,
+   then it can safely call `pytest_runtest_protocol` because it knows what the `nextitem` parameter will be.
+   If it receives a "shutdown" signal, then it can execute the hook passing `nextitem` as `None`.
+
 1. As tests are started and completed at the **workers**, the results are sent
-   back to the **master**, which then just forwards the results to 
-   the appropriate pytest hooks: `pytest_runtest_logstart` and 
+   back to the **master**, which then just forwards the results to
+   the appropriate pytest hooks: `pytest_runtest_logstart` and
    `pytest_runtest_logreport`. This way other plugins (for example `junitxml`)
-   can work normally. The **master** (when in dist-mode **load**) 
+   can work normally. The **master** (when in dist-mode **load**)
    decides to send more tests to a node when a test completes, using
    some heuristics such as test durations and how many tests each **worker**
    still has to run.
-   
+
 1. When the **master** has no more pending tests it will
-   send a "shutdown" signal to all **workers**, which will then run their 
-   remaining tests to completion and shut down. At this point the 
+   send a "shutdown" signal to all **workers**, which will then run their
+   remaining tests to completion and shut down. At this point the
    **master** will sit waiting for **workers** to shut down, still
    processing events such as `pytest_runtest_logreport`.
- 
+
 ## FAQ ##
 
-> Why does each worker do its own collection, as opposed to having 
+> Why does each worker do its own collection, as opposed to having
 the master collect once and distribute from that collection to the workers?
 
-If collection was performed by master then it would have to 
-serialize collected items to send them through the wire, as workers live in another process. 
-The problem is that test items are not easily (impossible?) to serialize, as they contain references to 
-the test functions, fixture managers, config objects, etc. Even if one manages to serialize it, 
-it seems it would be very hard to get it right and easy to break by any small change in pytest. 
-  
-
+If collection was performed by master then it would have to
+serialize collected items to send them through the wire, as workers live in another process.
+The problem is that test items are not easily (impossible?) to serialize, as they contain references to
+the test functions, fixture managers, config objects, etc. Even if one manages to serialize it,
+it seems it would be very hard to get it right and easy to break by any small change in pytest.

README.rst

@@ -4,14 +4,13 @@
     :alt: PyPI version
     :target: https://pypi.python.org/pypi/pytest-xdist
 
+.. image:: https://img.shields.io/conda/vn/conda-forge/pytest-xdist.svg
+    :target: https://anaconda.org/conda-forge/pytest-xdist
+
 .. image:: https://img.shields.io/pypi/pyversions/pytest-xdist.svg
     :alt: Python versions
     :target: https://pypi.python.org/pypi/pytest-xdist
 
-.. image:: https://anaconda.org/conda-forge/pytest-xdist/badges/version.svg
-    :alt: Anaconda version
-    :target: https://anaconda.org/conda-forge/pytest-xdist
-
 .. image:: https://travis-ci.org/pytest-dev/pytest-xdist.svg?branch=master
     :alt: Travis CI build status
     :target: https://travis-ci.org/pytest-dev/pytest-xdist
@@ -20,10 +19,13 @@
     :alt: AppVeyor build status
     :target: https://ci.appveyor.com/project/pytestbot/pytest-xdist
 
+.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
+    :target: https://github.com/ambv/black
+
 xdist: pytest distributed testing plugin
 ========================================
 
-The `pytest-xdist`_ plugin extends py.test with some unique
+The `pytest-xdist`_ plugin extends pytest with some unique
 test execution modes:
 
 * test run parallelization_: if you have multiple CPUs or hosts you can use
@@ -32,19 +34,19 @@ test execution modes:
 
 
 * ``--looponfail``: run your tests repeatedly in a subprocess.  After each run
-  py.test waits until a file in your project changes and then re-runs
+  pytest waits until a file in your project changes and then re-runs
   the previously failing tests.  This is repeated until all tests pass
   after which again a full run is performed.
 
 * `Multi-Platform`_ coverage: you can specify different Python interpreters
   or different platforms and run tests in parallel on all of them.
 
-Before running tests remotely, ``py.test`` efficiently "rsyncs" your
+Before running tests remotely, ``pytest`` efficiently "rsyncs" your
 program source code to the remote place.  All test results
 are reported back and displayed to your local terminal.
 You may specify different Python versions and interpreters.
 
-If you would like to know how pytest-xdist works under the covers, checkout 
+If you would like to know how pytest-xdist works under the covers, checkout
 `OVERVIEW <https://github.com/pytest-dev/pytest-xdist/blob/master/OVERVIEW.md>`_.
 
 
@@ -67,7 +69,7 @@ Speed up test runs by sending tests to multiple CPUs
 
 To send tests to multiple CPUs, type::
 
-    py.test -n NUM
+    pytest -n NUM
 
 Especially for longer running tests or tests requiring
 a lot of I/O this can lead to considerable speed ups. This option can
@@ -98,7 +100,7 @@ Running tests in a Python subprocess
 
 To instantiate a python3.5 subprocess and send tests to it, you may type::
 
-    py.test -d --tx popen//python=python3.5
+    pytest -d --tx popen//python=python3.5
 
 This will start a subprocess which is run with the ``python3.5``
 Python interpreter, found in your system binary lookup path.
@@ -129,10 +131,10 @@ tests that you can successfully run locally. And you
 have a ssh-reachable machine ``myhost``.  Then
 you can ad-hoc distribute your tests by typing::
 
-    py.test -d --tx ssh=myhostpopen --rsyncdir mypkg mypkg
+    pytest -d --tx ssh=myhostpopen --rsyncdir mypkg mypkg
 
 This will synchronize your :code:`mypkg` package directory
-to an remote ssh account and then locally collect tests
+to a remote ssh account and then locally collect tests
 and send them to remote places for execution.
 
 You can specify multiple :code:`--rsyncdir` directories
@@ -140,11 +142,11 @@ to be sent to the remote side.
 
 .. note::
 
-  For py.test to collect and send tests correctly
+  For pytest to collect and send tests correctly
   you not only need to make sure all code and tests
   directories are rsynced, but that any test (sub) directory
   also has an :code:`__init__.py` file because internally
-  py.test references tests as a fully qualified python
+  pytest references tests as a fully qualified python
   module path.  **You will otherwise get strange errors**
   during setup of the remote side.
 
@@ -168,7 +170,7 @@ It will tell you that it starts listening on the default
 port.  You can now on your home machine specify this
 new socket host with something like this::
 
-    py.test -d --tx socket=192.168.1.102:8888 --rsyncdir mypkg mypkg
+    pytest -d --tx socket=192.168.1.102:8888 --rsyncdir mypkg mypkg
 
 
 .. _`atonce`:
@@ -180,7 +182,7 @@ Running tests on many platforms at once
 
 The basic command to run tests on multiple platforms is::
 
-    py.test --dist=each --tx=spec1 --tx=spec2
+    pytest --dist=each --tx=spec1 --tx=spec2
 
 If you specify a windows host, an OSX host and a Linux
 environment this command will send each tests to all
@@ -242,7 +244,7 @@ You can also add default environments like this:
 
 and then just type::
 
-    py.test --dist=each
+    pytest --dist=each
 
 to run tests in each of the environments.
 

appveyor.yml

@@ -5,15 +5,19 @@ environment:
   - TOXENV: "py34-pytest33"
   - TOXENV: "py35-pytest33"
   - TOXENV: "py36-pytest33"
+  - TOXENV: "py36-pytest36"
+  - TOXENV: "py36-pytest38"
   - TOXENV: "py27-pytest33-pexpect"
   - TOXENV: "py36-pytest33-pexpect"
-  - TOXENV: "flakes"
-  - TOXENV: "readme"
 
 install:
-  - C:\Python35\python -m pip install -U tox setuptools_scm pip
+  - C:\Python36\python -m pip install -U tox setuptools_scm pip
 
 build: false  # Not a C# project, build stuff at the test step instead.
 
 test_script:
-  - C:\Python35\python -m tox
+  - C:\Python36\python -m tox
+
+# We don't deploy anything on tags with AppVeyor, we use Travis instead, so we
+# might as well save resources
+skip_tags: true

changelog/_template.rst

@@ -13,8 +13,7 @@
 
 {% if definitions[category]['showcontent'] %}
 {% for text, values in sections[section][category]|dictsort(by='value') %}
-- {{ text }}{% if category != 'vendor' %} (`{{ values[0] }} <https://github.com/pytest-dev/pytest-xdist/issues/{{ values[0][1:] }}>`_){% endif %}
-
+- `{{ values[0] }} <https://github.com/pytest-dev/pytest-xdist/issues/{{ values[0][1:] }}>`_: {{ text }}
 
 {% endfor %}
 {% else %}

dev-requirements.txt

@@ -1 +0,0 @@
-towncrier

example/boxed.txt

@@ -1,8 +1,8 @@
 .. note::
 
-  Since 1.19.0, the actual implementation of the ``--boxed`` option has been moved to a 
-  separate plugin, `pytest-forked <https://github.com/pytest-dev/pytest-forked>`_ 
-  which can be installed independently. The ``--boxed`` command-line options remains 
+  Since 1.19.0, the actual implementation of the ``--boxed`` option has been moved to a
+  separate plugin, `pytest-forked <https://github.com/pytest-dev/pytest-forked>`_
+  which can be installed independently. The ``--boxed`` command-line options remains
   for backward compatibility reasons.
 
 
@@ -25,7 +25,7 @@ to run each test in a controlled subprocess.  Here is a basic example::
 
 If you run this with::
 
-    $ py.test -n1
+    $ pytest -n1
     =========================== test session starts ============================
     platform linux2 -- Python 2.7.3 -- pytest-2.3.0.dev8
     plugins: xdist, bugzilla, cache, oejskit, cli, pep8, cov
@@ -46,7 +46,7 @@ You'll see that a couple of tests are reported as crashing, indicated
 by lower-case ``f`` and the respective failure summary. You can also use
 the xdist-provided parallelization feature to speed up your testing::
 
-    $ py.test -n3
+    $ pytest -n3
     =========================== test session starts ============================
     platform linux2 -- Python 2.7.3 -- pytest-2.3.0.dev8
     plugins: xdist, bugzilla, cache, oejskit, cli, pep8, cov

example/loadscope/test/test_delta.py

@@ -3,7 +3,6 @@ from unittest import TestCase
 
 
 class Delta1(TestCase):
-
     def test_delta0(self):
         sleep(5)
         assert True
@@ -46,7 +45,6 @@ class Delta1(TestCase):
 
 
 class Delta2(TestCase):
-
     def test_delta0(self):
         sleep(5)
         assert True

example/loadscope/tox.ini

@@ -8,7 +8,7 @@ passenv = http_proxy https_proxy
 deps = -rrequirements.txt
 changedir = {envtmpdir}
 commands =
-    py.test -s -v \
+    pytest -s -v \
         --doctest-modules \
         --junitxml=tests.xml \
         --dist=loadscope \

setup.py

@@ -1,47 +1,44 @@
 from setuptools import setup, find_packages
 
-install_requires = ['execnet>=1.1', 'pytest>=3.0.0', 'pytest-forked']
+install_requires = ["execnet>=1.1", "pytest>=3.0.0", "pytest-forked", "six"]
 
 
 setup(
     name="pytest-xdist",
-    use_scm_version={'write_to': 'xdist/_version.py'},
-    description='py.test xdist plugin for distributed testing'
-                ' and loop-on-failing modes',
-    long_description=open('README.rst').read(),
-    license='MIT',
-    author='holger krekel and contributors',
-    author_email='pytest-dev@python.org,holger@merlinux.eu',
-    url='https://github.com/pytest-dev/pytest-xdist',
-    platforms=['linux', 'osx', 'win32'],
-    packages=find_packages(exclude=['testing', 'example']),
+    use_scm_version={"write_to": "xdist/_version.py"},
+    description="pytest xdist plugin for distributed testing"
+    " and loop-on-failing modes",
+    long_description=open("README.rst").read(),
+    license="MIT",
+    author="holger krekel and contributors",
+    author_email="pytest-dev@python.org,holger@merlinux.eu",
+    url="https://github.com/pytest-dev/pytest-xdist",
+    platforms=["linux", "osx", "win32"],
+    packages=find_packages(exclude=["testing", "example"]),
     entry_points={
-        'pytest11': [
-            'xdist = xdist.plugin',
-            'xdist.looponfail = xdist.looponfail',
-        ],
+        "pytest11": ["xdist = xdist.plugin", "xdist.looponfail = xdist.looponfail"]
     },
     zip_safe=False,
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
+    python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
     install_requires=install_requires,
-    setup_requires=['setuptools_scm'],
+    setup_requires=["setuptools_scm"],
     classifiers=[
-        'Development Status :: 5 - Production/Stable',
-        'Framework :: Pytest',
-        'Intended Audience :: Developers',
-        'License :: OSI Approved :: MIT License',
-        'Operating System :: POSIX',
-        'Operating System :: Microsoft :: Windows',
-        'Operating System :: MacOS :: MacOS X',
-        'Topic :: Software Development :: Testing',
-        'Topic :: Software Development :: Quality Assurance',
-        'Topic :: Utilities',
-        'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
+        "Development Status :: 5 - Production/Stable",
+        "Framework :: Pytest",
+        "Intended Audience :: Developers",
+        "License :: OSI Approved :: MIT License",
+        "Operating System :: POSIX",
+        "Operating System :: Microsoft :: Windows",
+        "Operating System :: MacOS :: MacOS X",
+        "Topic :: Software Development :: Testing",
+        "Topic :: Software Development :: Quality Assurance",
+        "Topic :: Utilities",
+        "Programming Language :: Python",
+        "Programming Language :: Python :: 2",
+        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.4",
+        "Programming Language :: Python :: 3.5",
+        "Programming Language :: Python :: 3.6",
     ],
 )

testing/conftest.py

@@ -20,6 +20,7 @@ pytest_plugins = "pytester"
 @pytest.fixture(autouse=True)
 def _divert_atexit(request, monkeypatch):
     import atexit
+
     finalizers = []
 
     def finish():
@@ -31,10 +32,12 @@ def _divert_atexit(request, monkeypatch):
 
 
 def pytest_addoption(parser):
-    parser.addoption('--gx',
-                     action="append",
-                     dest="gspecs",
-                     help="add a global test environment, XSpec-syntax. ")
+    parser.addoption(
+        "--gx",
+        action="append",
+        dest="gspecs",
+        help="add a global test environment, XSpec-syntax. ",
+    )
 
 
 @pytest.fixture

testing/test_dsession.py

@@ -1,9 +1,6 @@
 from xdist.dsession import DSession
 from xdist.report import report_collection_diff
-from xdist.scheduler import (
-    EachScheduling,
-    LoadScheduling,
-)
+from xdist.scheduler import EachScheduling, LoadScheduling
 
 import py
 import pytest
@@ -60,7 +57,7 @@ class TestEachScheduling:
         sched = EachScheduling(config)
         sched.add_node(node1)
         sched.add_node(node2)
-        collection = ["a.py::test_1", ]
+        collection = ["a.py::test_1"]
         assert not sched.collection_is_completed
         sched.add_node_collection(node1, collection)
         assert not sched.collection_is_completed
@@ -70,8 +67,8 @@ class TestEachScheduling:
         assert sched.node2collection[node2] == collection
         sched.schedule()
         assert sched.tests_finished
-        assert node1.sent == ['ALL']
-        assert node2.sent == ['ALL']
+        assert node1.sent == ["ALL"]
+        assert node2.sent == ["ALL"]
         sched.mark_test_complete(node1, 0)
         assert sched.tests_finished
         sched.mark_test_complete(node2, 0)
@@ -82,7 +79,7 @@ class TestEachScheduling:
         config = testdir.parseconfig("--tx=popen")
         sched = EachScheduling(config)
         sched.add_node(node1)
-        collection = ["a.py::test_1", ]
+        collection = ["a.py::test_1"]
         assert not sched.collection_is_completed
         sched.add_node_collection(node1, collection)
         assert sched.collection_is_completed
@@ -230,7 +227,7 @@ class TestLoadScheduling:
         sched.schedule()
         assert len(collect_hook.reports) == 1
         rep = collect_hook.reports[0]
-        assert 'Different tests were collected between' in rep.longrepr
+        assert "Different tests were collected between" in rep.longrepr
 
 
 class TestDistReporter:
@@ -238,6 +235,7 @@ class TestDistReporter:
     def test_rsync_printing(self, testdir, linecomp):
         config = testdir.parseconfig()
         from _pytest.pytest_terminal import TerminalReporter
+
         rep = TerminalReporter(config, file=linecomp.stringio)
         config.pluginmanager.register(rep, "terminalreporter")
         dsession = DSession(config)
@@ -249,6 +247,7 @@ class TestDistReporter:
         class gw2:
             id = "X2"
             spec = execnet.XSpec("popen")
+
         # class rinfo:
         #    version_info = (2, 5, 1, 'final', 0)
         #    executable = "hello"
@@ -260,47 +259,50 @@ class TestDistReporter:
         #     "*X1*popen*xyz*2.5*"
         # ])
         dsession.pytest_xdist_rsyncstart(source="hello", gateways=[gw1, gw2])
-        linecomp.assert_contains_lines(["[X1,X2] rsyncing: hello", ])
+        linecomp.assert_contains_lines(["[X1,X2] rsyncing: hello"])
 
 
 def test_report_collection_diff_equal():
     """Test reporting of equal collections."""
-    from_collection = to_collection = ['aaa', 'bbb', 'ccc']
+    from_collection = to_collection = ["aaa", "bbb", "ccc"]
     assert report_collection_diff(from_collection, to_collection, 1, 2) is None
 
 
 def test_report_collection_diff_different():
     """Test reporting of different collections."""
-    from_collection = ['aaa', 'bbb', 'ccc', 'YYY']
-    to_collection = ['aZa', 'bbb', 'XXX', 'ccc']
+    from_collection = ["aaa", "bbb", "ccc", "YYY"]
+    to_collection = ["aZa", "bbb", "XXX", "ccc"]
     error_message = (
-        'Different tests were collected between 1 and 2. The difference is:\n'
-        '--- 1\n'
-        '\n'
-        '+++ 2\n'
-        '\n'
-        '@@ -1,4 +1,4 @@\n'
-        '\n'
-        '-aaa\n'
-        '+aZa\n'
-        ' bbb\n'
-        '+XXX\n'
-        ' ccc\n'
-        '-YYY')
+        "Different tests were collected between 1 and 2. The difference is:\n"
+        "--- 1\n"
+        "\n"
+        "+++ 2\n"
+        "\n"
+        "@@ -1,4 +1,4 @@\n"
+        "\n"
+        "-aaa\n"
+        "+aZa\n"
+        " bbb\n"
+        "+XXX\n"
+        " ccc\n"
+        "-YYY"
+    )
 
-    msg = report_collection_diff(from_collection, to_collection, '1', '2')
+    msg = report_collection_diff(from_collection, to_collection, "1", "2")
     assert msg == error_message
 
 
 @pytest.mark.xfail(reason="duplicate test ids not supported yet")
 def test_pytest_issue419(testdir):
-    testdir.makepyfile("""
+    testdir.makepyfile(
+        """
         import pytest
 
         @pytest.mark.parametrize('birth_year', [1988, 1988, ])
         def test_2011_table(birth_year):
             pass
-    """)
+    """
+    )
     reprec = testdir.inline_run("-n1")
     reprec.assertoutcome(passed=2)
     assert 0

testing/test_looponfail.py

@@ -60,7 +60,7 @@ class TestStatRecorder:
         p.remove()
         # make check()'s visit() call return our just removed
         # path as if we were in a race condition
-        monkeypatch.setattr(tmp, 'visit', lambda *args: [p])
+        monkeypatch.setattr(tmp, "visit", lambda *args: [p])
 
         changed = sd.check()
         assert changed
@@ -84,7 +84,7 @@ class TestStatRecorder:
         sd = StatRecorder([tmp])
 
         ret_values = [True, False]
-        monkeypatch.setattr(StatRecorder, 'check', lambda self: ret_values.pop())
+        monkeypatch.setattr(StatRecorder, "check", lambda self: ret_values.pop())
         sd.waitonchange(checkinterval=0.2)
         assert not ret_values
 
@@ -110,19 +110,25 @@ class TestRemoteControl:
         assert not failures
 
     def test_failure_change(self, testdir):
-        modcol = testdir.getitem("""
+        modcol = testdir.getitem(
+            """
             def test_func():
                 assert 0
-        """)
+        """
+        )
         control = RemoteControl(modcol.config)
         control.loop_once()
         assert control.failures
-        modcol.fspath.write(py.code.Source("""
+        modcol.fspath.write(
+            py.code.Source(
+                """
             def test_func():
                 assert 1
             def test_new():
                 assert 0
-        """))
+        """
+            )
+        )
         removepyc(modcol.fspath)
         control.loop_once()
         assert not control.failures
@@ -131,14 +137,17 @@ class TestRemoteControl:
         assert str(control.failures).find("test_new") != -1
 
     def test_failure_subdir_no_init(self, testdir):
-        modcol = testdir.getitem("""
+        modcol = testdir.getitem(
+            """
             def test_func():
                 assert 0
-        """)
+        """
+        )
         parent = modcol.fspath.dirpath().dirpath()
         parent.chdir()
-        modcol.config.args = [py.path.local(x).relto(parent)
-                              for x in modcol.config.args]
+        modcol.config.args = [
+            py.path.local(x).relto(parent) for x in modcol.config.args
+        ]
         control = RemoteControl(modcol.config)
         control.loop_once()
         assert control.failures
@@ -148,70 +157,87 @@ class TestRemoteControl:
 
 class TestLooponFailing:
     def test_looponfail_from_fail_to_ok(self, testdir):
-        modcol = testdir.getmodulecol("""
+        modcol = testdir.getmodulecol(
+            """
             def test_one():
                 x = 0
                 assert x == 1
             def test_two():
                 assert 1
-        """)
+        """
+        )
         remotecontrol = RemoteControl(modcol.config)
         remotecontrol.loop_once()
         assert len(remotecontrol.failures) == 1
 
-        modcol.fspath.write(py.code.Source("""
+        modcol.fspath.write(
+            py.code.Source(
+                """
             def test_one():
                 assert 1
             def test_two():
                 assert 1
-        """))
+        """
+            )
+        )
         removepyc(modcol.fspath)
         remotecontrol.loop_once()
         assert not remotecontrol.failures
 
     def test_looponfail_from_one_to_two_tests(self, testdir):
-        modcol = testdir.getmodulecol("""
+        modcol = testdir.getmodulecol(
+            """
             def test_one():
                 assert 0
-        """)
+        """
+        )
         remotecontrol = RemoteControl(modcol.config)
         remotecontrol.loop_once()
         assert len(remotecontrol.failures) == 1
-        assert 'test_one' in remotecontrol.failures[0]
+        assert "test_one" in remotecontrol.failures[0]
 
-        modcol.fspath.write(py.code.Source("""
+        modcol.fspath.write(
+            py.code.Source(
+                """
             def test_one():
                 assert 1 # passes now
             def test_two():
                 assert 0 # new and fails
-        """))
+        """
+            )
+        )
         removepyc(modcol.fspath)
         remotecontrol.loop_once()
         assert len(remotecontrol.failures) == 0
         remotecontrol.loop_once()
         assert len(remotecontrol.failures) == 1
-        assert 'test_one' not in remotecontrol.failures[0]
-        assert 'test_two' in remotecontrol.failures[0]
+        assert "test_one" not in remotecontrol.failures[0]
+        assert "test_two" in remotecontrol.failures[0]
 
-    @py.test.mark.xfail(py.test.__version__ >= "3.1",
-                        reason="broken by pytest 3.1+")
+    @py.test.mark.xfail(py.test.__version__ >= "3.1", reason="broken by pytest 3.1+")
     def test_looponfail_removed_test(self, testdir):
-        modcol = testdir.getmodulecol("""
+        modcol = testdir.getmodulecol(
+            """
             def test_one():
                 assert 0
             def test_two():
                 assert 0
-        """)
+        """
+        )
         remotecontrol = RemoteControl(modcol.config)
         remotecontrol.loop_once()
         assert len(remotecontrol.failures) == 2
 
-        modcol.fspath.write(py.code.Source("""
+        modcol.fspath.write(
+            py.code.Source(
+                """
             def test_xxx(): # renamed test
                 assert 0
             def test_two():
                 assert 1 # pass now
-        """))
+        """
+            )
+        )
         removepyc(modcol.fspath)
         remotecontrol.loop_once()
         assert len(remotecontrol.failures) == 0
@@ -220,10 +246,12 @@ class TestLooponFailing:
         assert len(remotecontrol.failures) == 1
 
     def test_looponfail_multiple_errors(self, testdir, monkeypatch):
-        modcol = testdir.getmodulecol("""
+        modcol = testdir.getmodulecol(
+            """
             def test_one():
                 assert 0
-        """)
+        """
+        )
         remotecontrol = RemoteControl(modcol.config)
         orig_runsession = remotecontrol.runsession
 
@@ -233,18 +261,20 @@ class TestLooponFailing:
             print(failures)
             return failures * 2, reports, collection_failed
 
-        monkeypatch.setattr(remotecontrol, 'runsession', runsession_dups)
+        monkeypatch.setattr(remotecontrol, "runsession", runsession_dups)
         remotecontrol.loop_once()
         assert len(remotecontrol.failures) == 1
 
 
 class TestFunctional:
     def test_fail_to_ok(self, testdir):
-        p = testdir.makepyfile("""
+        p = testdir.makepyfile(
+            """
             def test_one():
                 x = 0
                 assert x == 1
-        """)
+        """
+        )
         # p = testdir.mkdir("sub").join(p1.basename)
         # p1.move(p)
         child = testdir.spawn_pytest("-f %s --traceconfig" % p)
@@ -253,21 +283,27 @@ class TestFunctional:
         child.expect("1 failed")
         child.expect("### LOOPONFAILING ####")
         child.expect("waiting for changes")
-        p.write(py.code.Source("""
+        p.write(
+            py.code.Source(
+                """
             def test_one():
                 x = 1
                 assert x == 1
-        """))
+        """
+            )
+        )
         child.expect(".*1 passed.*")
         child.kill(15)
 
     def test_xfail_passes(self, testdir):
-        p = testdir.makepyfile("""
+        p = testdir.makepyfile(
+            """
             import py
             @py.test.mark.xfail
             def test_one():
                 pass
-        """)
+        """
+        )
         child = testdir.spawn_pytest("-f %s" % p)
         child.expect("1 xpass")
         # child.expect("### LOOPONFAILING ####")

testing/test_newhooks.py

@@ -2,21 +2,23 @@ import pytest
 
 
 class TestHooks:
-
     @pytest.fixture(autouse=True)
     def create_test_file(self, testdir):
-        testdir.makepyfile("""
+        testdir.makepyfile(
+            """
             import os
             def test_a(): pass
             def test_b(): pass
             def test_c(): pass
-        """)
+        """
+        )
 
     def test_runtest_logreport(self, testdir):
         """Test that log reports from pytest_runtest_logreport when running
         with xdist contain "node", "nodeid" and "worker_id" attributes. (#8)
         """
-        testdir.makeconftest("""
+        testdir.makeconftest(
+            """
             def pytest_runtest_logreport(report):
                 if hasattr(report, 'node'):
                     if report.when == "call":
@@ -27,29 +29,31 @@ class TestHooks:
                         else:
                             print("HOOK: %s %s"
                                    % (report.nodeid, report.worker_id))
-        """)
-        res = testdir.runpytest('-n1', '-s')
-        res.stdout.fnmatch_lines([
-            '*HOOK: test_runtest_logreport.py::test_a gw0*',
-            '*HOOK: test_runtest_logreport.py::test_b gw0*',
-            '*HOOK: test_runtest_logreport.py::test_c gw0*',
-            '*3 passed*',
-        ])
+        """
+        )
+        res = testdir.runpytest("-n1", "-s")
+        res.stdout.fnmatch_lines(
+            [
+                "*HOOK: test_runtest_logreport.py::test_a gw0*",
+                "*HOOK: test_runtest_logreport.py::test_b gw0*",
+                "*HOOK: test_runtest_logreport.py::test_c gw0*",
+                "*3 passed*",
+            ]
+        )
 
     def test_node_collection_finished(self, testdir):
         """Test pytest_xdist_node_collection_finished hook (#8).
         """
-        testdir.makeconftest("""
+        testdir.makeconftest(
+            """
             def pytest_xdist_node_collection_finished(node, ids):
                 workerid = node.workerinput['workerid']
                 stripped_ids = [x.split('::')[1] for x in ids]
                 print("HOOK: %s %s" % (workerid, ', '.join(stripped_ids)))
-        """)
-        res = testdir.runpytest('-n2', '-s')
-        res.stdout.fnmatch_lines_random([
-            '*HOOK: gw0 test_a, test_b, test_c',
-            '*HOOK: gw1 test_a, test_b, test_c',
-        ])
-        res.stdout.fnmatch_lines([
-            '*3 passed*',
-        ])
+        """
+        )
+        res = testdir.runpytest("-n2", "-s")
+        res.stdout.fnmatch_lines_random(
+            ["*HOOK: gw0 test_a, test_b, test_c", "*HOOK: gw1 test_a, test_b, test_c"]
+        )
+        res.stdout.fnmatch_lines(["*3 passed*"])

testing/test_plugin.py

@@ -16,14 +16,15 @@ def test_dist_incompatibility_messages(testdir):
 
 def test_dist_options(testdir):
     from xdist.plugin import pytest_cmdline_main as check_options
+
     config = testdir.parseconfigure("-n 2")
     check_options(config)
     assert config.option.dist == "load"
-    assert config.option.tx == ['popen'] * 2
+    assert config.option.tx == ["popen"] * 2
     config = testdir.parseconfigure("--numprocesses", "2")
     check_options(config)
     assert config.option.dist == "load"
-    assert config.option.tx == ['popen'] * 2
+    assert config.option.tx == ["popen"] * 2
     config = testdir.parseconfigure("-d")
     check_options(config)
     assert config.option.dist == "load"
@@ -31,21 +32,31 @@ def test_dist_options(testdir):
 
 def test_auto_detect_cpus(testdir, monkeypatch):
     import os
-    if hasattr(os, 'cpu_count'):
-        monkeypatch.setattr(os, 'cpu_count', lambda: 99)
+
+    if hasattr(os, "sched_getaffinity"):
+        monkeypatch.setattr(os, "sched_getaffinity", lambda _pid: set(range(99)))
+    elif hasattr(os, "cpu_count"):
+        monkeypatch.setattr(os, "cpu_count", lambda: 99)
     else:
         import multiprocessing
-        monkeypatch.setattr(multiprocessing, 'cpu_count', lambda: 99)
+
+        monkeypatch.setattr(multiprocessing, "cpu_count", lambda: 99)
 
     config = testdir.parseconfigure("-n2")
-    assert config.getoption('numprocesses') == 2
+    assert config.getoption("numprocesses") == 2
 
     config = testdir.parseconfigure("-nauto")
-    assert config.getoption('numprocesses') == 99
+    assert config.getoption("numprocesses") == 99
+
+    monkeypatch.delattr(os, "sched_getaffinity", raising=False)
+    monkeypatch.setenv("TRAVIS", "true")
+    config = testdir.parseconfigure("-nauto")
+    assert config.getoption("numprocesses") == 2
 
 
 def test_boxed_with_collect_only(testdir):
     from xdist.plugin import pytest_cmdline_main as check_options
+
     config = testdir.parseconfigure("-n1", "--boxed")
     check_options(config)
     assert config.option.forked
@@ -85,13 +96,13 @@ class TestDistOptions:
         assert xspecs[1].ssh == "xyz"
 
     def test_xspecs_multiplied(self, testdir):
-        config = testdir.parseconfigure("--tx=3*popen", )
+        config = testdir.parseconfigure("--tx=3*popen")
         xspecs = NodeManager(config)._getxspecs()
         assert len(xspecs) == 3
         assert xspecs[1].popen
 
     def test_getrsyncdirs(self, testdir):
-        config = testdir.parseconfigure('--rsyncdir=' + str(testdir.tmpdir))
+        config = testdir.parseconfigure("--rsyncdir=" + str(testdir.tmpdir))
         nm = NodeManager(config, specs=[execnet.XSpec("popen")])
         assert not nm._getrsyncdirs()
         nm = NodeManager(config, specs=[execnet.XSpec("popen//chdir=qwe")])
@@ -99,23 +110,24 @@ class TestDistOptions:
         assert testdir.tmpdir in nm.roots
 
     def test_getrsyncignore(self, testdir):
-        config = testdir.parseconfigure('--rsyncignore=fo*')
+        config = testdir.parseconfigure("--rsyncignore=fo*")
         nm = NodeManager(config, specs=[execnet.XSpec("popen//chdir=qwe")])
-        assert 'fo*' in nm.rsyncoptions['ignores']
+        assert "fo*" in nm.rsyncoptions["ignores"]
 
     def test_getrsyncdirs_with_conftest(self, testdir):
         p = py.path.local()
-        for bn in 'x y z'.split():
+        for bn in "x y z".split():
             p.mkdir(bn)
-        testdir.makeini("""
+        testdir.makeini(
+            """
             [pytest]
             rsyncdirs= x
-        """)
-        config = testdir.parseconfigure(
-            testdir.tmpdir, '--rsyncdir=y', '--rsyncdir=z')
+        """
+        )
+        config = testdir.parseconfigure(testdir.tmpdir, "--rsyncdir=y", "--rsyncdir=z")
         nm = NodeManager(config, specs=[execnet.XSpec("popen//chdir=xyz")])
         roots = nm._getrsyncdirs()
         # assert len(roots) == 3 + 1 # pylib
-        assert py.path.local('y') in roots
-        assert py.path.local('z') in roots
-        assert testdir.tmpdir.join('x') in roots
+        assert py.path.local("y") in roots
+        assert py.path.local("z") in roots
+        assert testdir.tmpdir.join("x") in roots

testing/test_remote.py

@@ -1,11 +1,12 @@
 import py
+import pprint
 import pytest
 from xdist.workermanage import WorkerController, unserialize_report
 from xdist.remote import serialize_report
 import execnet
 import marshal
 
-queue = py.builtin._tryimport("queue", "Queue")
+from six.moves.queue import Queue
 
 WAIT_TIMEOUT = 10.0
 
@@ -14,7 +15,7 @@ def check_marshallable(d):
     try:
         marshal.dumps(d)
     except ValueError:
-        py.std.pprint.pprint(d)
+        pprint.pprint(d)
         raise ValueError("not marshallable")
 
 
@@ -32,9 +33,9 @@ class WorkerSetup:
     def __init__(self, request, testdir):
         self.request = request
         self.testdir = testdir
-        self.events = queue.Queue()
+        self.events = Queue()
 
-    def setup(self, ):
+    def setup(self,):
         self.testdir.chdir()
         # import os ; os.environ['EXECNET_DEBUG'] = "2"
         self.gateway = execnet.makegateway()
@@ -44,8 +45,7 @@ class WorkerSetup:
         class DummyMananger:
             specs = [0, 1]
 
-        self.slp = WorkerController(DummyMananger, self.gateway, config,
-                                    putevent)
+        self.slp = WorkerController(DummyMananger, self.gateway, config, putevent)
         self.request.addfinalizer(self.slp.ensure_teardown)
         self.slp.setup()
 
@@ -58,7 +58,7 @@ class WorkerSetup:
             ev = EventCall(data)
             if name is None or ev.name == name:
                 return ev
-            print("skipping %s" % (ev, ))
+            print("skipping %s" % (ev,))
 
     def sendcommand(self, name, **kwargs):
         self.slp.sendcommand(name, **kwargs)
@@ -69,9 +69,10 @@ def worker(request, testdir):
     return WorkerSetup(request, testdir)
 
 
-@pytest.mark.xfail(reason='#59')
+@pytest.mark.xfail(reason="#59")
 def test_remoteinitconfig(testdir):
     from xdist.remote import remote_initconfig
+
     config1 = testdir.parseconfig()
     config2 = remote_initconfig(config1.option.__dict__, config1.args)
     assert config2.option.__dict__ == config1.option.__dict__
@@ -80,29 +81,33 @@ def test_remoteinitconfig(testdir):
 
 class TestReportSerialization:
     def test_xdist_longrepr_to_str_issue_241(self, testdir):
-        testdir.makepyfile("""
+        testdir.makepyfile(
+            """
             import os
             def test_a(): assert False
             def test_b(): pass
-        """)
-        testdir.makeconftest("""
+        """
+        )
+        testdir.makeconftest(
+            """
             def pytest_runtest_logreport(report):
                 print(report.longrepr)
-        """)
-        res = testdir.runpytest('-n1', '-s')
-        res.stdout.fnmatch_lines([
-            '*1 failed, 1 passed *'
-        ])
+        """
+        )
+        res = testdir.runpytest("-n1", "-s")
+        res.stdout.fnmatch_lines(["*1 failed, 1 passed *"])
 
     def test_xdist_report_longrepr_reprcrash_130(self, testdir):
-        reprec = testdir.inline_runsource("""
+        reprec = testdir.inline_runsource(
+            """
                     import py
                     def test_fail(): assert False, 'Expected Message'
-                """)
+                """
+        )
         reports = reprec.getreports("pytest_runtest_logreport")
         assert len(reports) == 3
         rep = reports[1]
-        added_section = ('Failure Metadata', str("metadata metadata"), "*")
+        added_section = ("Failure Metadata", str("metadata metadata"), "*")
         rep.longrepr.sections.append(added_section)
         d = serialize_report(rep)
         check_marshallable(d)
@@ -110,28 +115,31 @@ class TestReportSerialization:
         # Check assembled == rep
         assert a.__dict__.keys() == rep.__dict__.keys()
         for key in rep.__dict__.keys():
-            if key != 'longrepr':
+            if key != "longrepr":
                 assert getattr(a, key) == getattr(rep, key)
         assert rep.longrepr.reprcrash.lineno == a.longrepr.reprcrash.lineno
         assert rep.longrepr.reprcrash.message == a.longrepr.reprcrash.message
         assert rep.longrepr.reprcrash.path == a.longrepr.reprcrash.path
-        assert rep.longrepr.reprtraceback.entrysep \
-            == a.longrepr.reprtraceback.entrysep
-        assert rep.longrepr.reprtraceback.extraline \
-            == a.longrepr.reprtraceback.extraline
-        assert rep.longrepr.reprtraceback.style \
-            == a.longrepr.reprtraceback.style
+        assert rep.longrepr.reprtraceback.entrysep == a.longrepr.reprtraceback.entrysep
+        assert (
+            rep.longrepr.reprtraceback.extraline == a.longrepr.reprtraceback.extraline
+        )
+        assert rep.longrepr.reprtraceback.style == a.longrepr.reprtraceback.style
         assert rep.longrepr.sections == a.longrepr.sections
         # Missing section attribute PR171
         assert added_section in a.longrepr.sections
 
     def test_reprentries_serialization_170(self, testdir):
         from _pytest._code.code import ReprEntry
-        reprec = testdir.inline_runsource("""
+
+        reprec = testdir.inline_runsource(
+            """
                             def test_repr_entry():
                                 x = 0
                                 assert x
-                        """, '--showlocals')
+                        """,
+            "--showlocals",
+        )
         reports = reprec.getreports("pytest_runtest_logreport")
         assert len(reports) == 3
         rep = reports[1]
@@ -145,7 +153,9 @@ class TestReportSerialization:
             assert rep_entries[i].lines == a_entries[i].lines
             assert rep_entries[i].localssep == a_entries[i].localssep
             assert rep_entries[i].reprfileloc.lineno == a_entries[i].reprfileloc.lineno
-            assert rep_entries[i].reprfileloc.message == a_entries[i].reprfileloc.message
+            assert (
+                rep_entries[i].reprfileloc.message == a_entries[i].reprfileloc.message
+            )
             assert rep_entries[i].reprfileloc.path == a_entries[i].reprfileloc.path
             assert rep_entries[i].reprfuncargs.args == a_entries[i].reprfuncargs.args
             assert rep_entries[i].reprlocals.lines == a_entries[i].reprlocals.lines
@@ -153,11 +163,15 @@ class TestReportSerialization:
 
     def test_reprentries_serialization_196(self, testdir):
         from _pytest._code.code import ReprEntryNative
-        reprec = testdir.inline_runsource("""
+
+        reprec = testdir.inline_runsource(
+            """
                             def test_repr_entry_native():
                                 x = 0
                                 assert x
-                        """, '--tb=native')
+                        """,
+            "--tb=native",
+        )
         reports = reprec.getreports("pytest_runtest_logreport")
         assert len(reports) == 3
         rep = reports[1]
@@ -171,7 +185,8 @@ class TestReportSerialization:
             assert rep_entries[i].lines == a_entries[i].lines
 
     def test_itemreport_outcomes(self, testdir):
-        reprec = testdir.inline_runsource("""
+        reprec = testdir.inline_runsource(
+            """
             import py
             def test_pass(): pass
             def test_fail(): 0/0
@@ -183,7 +198,8 @@ class TestReportSerialization:
             def test_xfail(): 0/0
             def test_xfail_imperative():
                 py.test.xfail("hello")
-        """)
+        """
+        )
         reports = reprec.getreports("pytest_runtest_logreport")
         assert len(reports) == 17  # with setup/teardown "passed" reports
         for rep in reports:
@@ -245,10 +261,12 @@ class TestReportSerialization:
 
 class TestWorkerInteractor:
     def test_basic_collect_and_runtests(self, worker):
-        worker.testdir.makepyfile("""
+        worker.testdir.makepyfile(
+            """
             def test_func():
                 pass
-        """)
+        """
+        )
         worker.setup()
         ev = worker.popevent()
         assert ev.name == "workerready"
@@ -256,8 +274,8 @@ class TestWorkerInteractor:
         assert ev.name == "collectionstart"
         assert not ev.kwargs
         ev = worker.popevent("collectionfinish")
-        assert ev.kwargs['topdir'] == worker.testdir.tmpdir
-        ids = ev.kwargs['ids']
+        assert ev.kwargs["topdir"] == worker.testdir.tmpdir
+        ids = ev.kwargs["ids"]
         assert len(ids) == 1
         worker.sendcommand("runtests", indices=list(range(len(ids))))
         worker.sendcommand("shutdown")
@@ -267,20 +285,23 @@ class TestWorkerInteractor:
         ev = worker.popevent("testreport")  # setup
         ev = worker.popevent("testreport")
         assert ev.name == "testreport"
-        rep = unserialize_report(ev.name, ev.kwargs['data'])
+        rep = unserialize_report(ev.name, ev.kwargs["data"])
         assert rep.nodeid.endswith("::test_func")
         assert rep.passed
         assert rep.when == "call"
         ev = worker.popevent("workerfinished")
-        assert 'workeroutput' in ev.kwargs
+        assert "workeroutput" in ev.kwargs
 
-    @pytest.mark.skipif(pytest.__version__ >= '3.0',
-                        reason='skip at module level illegal in pytest 3.0')
+    @pytest.mark.skipif(
+        pytest.__version__ >= "3.0", reason="skip at module level illegal in pytest 3.0"
+    )
     def test_remote_collect_skip(self, worker):
-        worker.testdir.makepyfile("""
+        worker.testdir.makepyfile(
+            """
             import py
             py.test.skip("hello")
-        """)
+        """
+        )
         worker.setup()
         ev = worker.popevent("collectionstart")
         assert not ev.kwargs
@@ -288,10 +309,10 @@ class TestWorkerInteractor:
         assert ev.name == "collectreport"
         ev = worker.popevent()
         assert ev.name == "collectreport"
-        rep = unserialize_report(ev.name, ev.kwargs['data'])
+        rep = unserialize_report(ev.name, ev.kwargs["data"])
         assert rep.skipped
         ev = worker.popevent("collectionfinish")
-        assert not ev.kwargs['ids']
+        assert not ev.kwargs["ids"]
 
     def test_remote_collect_fail(self, worker):
         worker.testdir.makepyfile("""aasd qwe""")
@@ -300,18 +321,18 @@ class TestWorkerInteractor:
         assert not ev.kwargs
         ev = worker.popevent()
         assert ev.name == "collectreport"
-        ev = worker.popevent()
-        assert ev.name == "collectreport"
-        rep = unserialize_report(ev.name, ev.kwargs['data'])
+        rep = unserialize_report(ev.name, ev.kwargs["data"])
         assert rep.failed
         ev = worker.popevent("collectionfinish")
-        assert not ev.kwargs['ids']
+        assert not ev.kwargs["ids"]
 
     def test_runtests_all(self, worker):
-        worker.testdir.makepyfile("""
+        worker.testdir.makepyfile(
+            """
             def test_func(): pass
             def test_func2(): pass
-        """)
+        """
+        )
         worker.setup()
         ev = worker.popevent()
         assert ev.name == "workerready"
@@ -319,57 +340,63 @@ class TestWorkerInteractor:
         assert ev.name == "collectionstart"
         assert not ev.kwargs
         ev = worker.popevent("collectionfinish")
-        ids = ev.kwargs['ids']
+        ids = ev.kwargs["ids"]
         assert len(ids) == 2
-        worker.sendcommand("runtests_all", )
-        worker.sendcommand("shutdown", )
+        worker.sendcommand("runtests_all")
+        worker.sendcommand("shutdown")
         for func in "::test_func", "::test_func2":
             for i in range(3):  # setup/call/teardown
                 ev = worker.popevent("testreport")
                 assert ev.name == "testreport"
-                rep = unserialize_report(ev.name, ev.kwargs['data'])
+                rep = unserialize_report(ev.name, ev.kwargs["data"])
                 assert rep.nodeid.endswith(func)
         ev = worker.popevent("workerfinished")
-        assert 'workeroutput' in ev.kwargs
+        assert "workeroutput" in ev.kwargs
 
     def test_happy_run_events_converted(self, testdir, worker):
         py.test.xfail("implement a simple test for event production")
         assert not worker.use_callback
-        worker.testdir.makepyfile("""
+        worker.testdir.makepyfile(
+            """
             def test_func():
                 pass
-        """)
+        """
+        )
         worker.setup()
         hookrec = testdir.getreportrecorder(worker.config)
         for data in worker.slp.channel:
             worker.slp.process_from_remote(data)
         worker.slp.process_from_remote(worker.slp.ENDMARK)
-        py.std.pprint.pprint(hookrec.hookrecorder.calls)
-        hookrec.hookrecorder.contains([
-            ("pytest_collectstart", "collector.fspath == aaa"),
-            ("pytest_pycollect_makeitem", "name == 'test_func'"),
-            ("pytest_collectreport", "report.collector.fspath == aaa"),
-            ("pytest_collectstart", "collector.fspath == bbb"),
-            ("pytest_pycollect_makeitem", "name == 'test_func'"),
-            ("pytest_collectreport", "report.collector.fspath == bbb"),
-        ])
+        pprint.pprint(hookrec.hookrecorder.calls)
+        hookrec.hookrecorder.contains(
+            [
+                ("pytest_collectstart", "collector.fspath == aaa"),
+                ("pytest_pycollect_makeitem", "name == 'test_func'"),
+                ("pytest_collectreport", "report.collector.fspath == aaa"),
+                ("pytest_collectstart", "collector.fspath == bbb"),
+                ("pytest_pycollect_makeitem", "name == 'test_func'"),
+                ("pytest_collectreport", "report.collector.fspath == bbb"),
+            ]
+        )
 
     def test_process_from_remote_error_handling(self, worker, capsys):
         worker.use_callback = True
         worker.setup()
-        worker.slp.process_from_remote(('<nonono>', ()))
+        worker.slp.process_from_remote(("<nonono>", ()))
         out, err = capsys.readouterr()
-        assert 'INTERNALERROR> ValueError: unknown event: <nonono>' in out
+        assert "INTERNALERROR> ValueError: unknown event: <nonono>" in out
         ev = worker.popevent()
         assert ev.name == "errordown"
 
 
 def test_remote_env_vars(testdir):
-    testdir.makepyfile('''
+    testdir.makepyfile(
+        """
         import os
         def test():
             assert os.environ['PYTEST_XDIST_WORKER'] in ('gw0', 'gw1')
             assert os.environ['PYTEST_XDIST_WORKER_COUNT'] == '2'
-    ''')
-    result = testdir.runpytest('-n2', '--max-worker-restart=0')
+    """
+    )
+    result = testdir.runpytest("-n2", "--max-worker-restart=0")
     assert result.ret == 0

testing/test_slavemanage.py

@@ -1,5 +1,7 @@
+from __future__ import print_function
 import py
 import pytest
+import textwrap
 import execnet
 from _pytest.pytester import HookRecorder
 from xdist import workermanage, newhooks
@@ -40,7 +42,7 @@ def workercontroller(monkeypatch):
         def setup(self):
             pass
 
-    monkeypatch.setattr(workermanage, 'WorkerController', MockController)
+    monkeypatch.setattr(workermanage, "WorkerController", MockController)
     return MockController
 
 
@@ -56,8 +58,7 @@ class TestNodeManagerPopen:
         for spec in NodeManager(config, specs, defaultchdir="abc").specs:
             assert spec.chdir == "abc"
 
-    def test_popen_makegateway_events(self, config, hookrecorder,
-                                      workercontroller):
+    def test_popen_makegateway_events(self, config, hookrecorder, workercontroller):
         hm = NodeManager(config, ["popen"] * 2)
         hm.setup_nodes(None)
         call = hookrecorder.popcall("pytest_xdist_setupnodes")
@@ -106,15 +107,16 @@ class TestNodeManagerPopen:
         for gw in hm.group:
             hm.rsync(gw, source, notify=lambda *args: notifications.append(args))
         assert len(notifications) == 1
-        assert notifications[0] == ("rsyncrootready", hm.group['gw0'].spec, source)
+        assert notifications[0] == ("rsyncrootready", hm.group["gw0"].spec, source)
         hm.teardown_nodes()
         dest = dest.join(source.basename)
         assert dest.join("dir1").check()
         assert dest.join("dir1", "dir2").check()
-        assert dest.join("dir1", "dir2", 'hello').check()
+        assert dest.join("dir1", "dir2", "hello").check()
 
-    def test_rsync_same_popen_twice(self, config, mysetup, hookrecorder,
-                                    workercontroller):
+    def test_rsync_same_popen_twice(
+        self, config, mysetup, hookrecorder, workercontroller
+    ):
         source, dest = mysetup.source, mysetup.dest
         hm = NodeManager(config, ["popen//chdir=%s" % dest] * 2)
         hm.roots = []
@@ -140,9 +142,9 @@ class TestHRSync:
         files = list(source.visit(rec=syncer.filter, fil=syncer.filter))
         assert len(files) == 3
         basenames = [x.basename for x in files]
-        assert 'dir' in basenames
-        assert 'file.txt' in basenames
-        assert 'somedir' in basenames
+        assert "dir" in basenames
+        assert "file.txt" in basenames
+        assert "somedir" in basenames
 
     def test_hrsync_one_host(self, mysetup):
         source, dest = mysetup.source, mysetup.dest
@@ -167,9 +169,10 @@ class TestNodeManager:
         nodemanager.makegateways()
         nodemanager.rsync_roots()
         p, = nodemanager.gwmanager.multi_exec(
-            "import os ; channel.send(os.getcwd())").receive_each()
+            "import os ; channel.send(os.getcwd())"
+        ).receive_each()
         p = py.path.local(p)
-        py.builtin.print_("remote curdir", p)
+        print("remote curdir", p)
         assert p == mysetup.dest.join(config.topdir.basename)
         assert p.join("dir1").check()
         assert p.join("dir1", "file1").check()
@@ -181,15 +184,17 @@ class TestNodeManager:
         dir2.ensure("hello")
         for rsyncroot in (dir1, source):
             dest.remove()
-            nodemanager = NodeManager(testdir.parseconfig(
-                "--tx", "popen//chdir=%s" % dest, "--rsyncdir", rsyncroot,
-                source, ))
+            nodemanager = NodeManager(
+                testdir.parseconfig(
+                    "--tx", "popen//chdir=%s" % dest, "--rsyncdir", rsyncroot, source
+                )
+            )
             nodemanager.setup_nodes(None)  # calls .rsync_roots()
             if rsyncroot == source:
                 dest = dest.join("source")
             assert dest.join("dir1").check()
             assert dest.join("dir1", "dir2").check()
-            assert dest.join("dir1", "dir2", 'hello').check()
+            assert dest.join("dir1", "dir2", "hello").check()
             nodemanager.teardown_nodes()
 
     def test_init_rsync_roots(self, testdir, mysetup, workercontroller):
@@ -198,10 +203,14 @@ class TestNodeManager:
         source.ensure("dir1", "somefile", dir=1)
         dir2.ensure("hello")
         source.ensure("bogusdir", "file")
-        source.join("tox.ini").write(py.std.textwrap.dedent("""
+        source.join("tox.ini").write(
+            textwrap.dedent(
+                """
             [pytest]
             rsyncdirs=dir1/dir2
-        """))
+        """
+            )
+        )
         config = testdir.parseconfig(source)
         nodemanager = NodeManager(config, ["popen//chdir=%s" % dest])
         nodemanager.setup_nodes(None)  # calls .rsync_roots()
@@ -217,27 +226,31 @@ class TestNodeManager:
         dir2.ensure("hello")
         source.ensure("foo", "bar")
         source.ensure("bar", "foo")
-        source.join("tox.ini").write(py.std.textwrap.dedent("""
+        source.join("tox.ini").write(
+            textwrap.dedent(
+                """
             [pytest]
             rsyncdirs = dir1 dir5
             rsyncignore = dir1/dir2 dir5/dir6 foo*
-        """))
+        """
+            )
+        )
         config = testdir.parseconfig(source)
-        config.option.rsyncignore = ['bar']
+        config.option.rsyncignore = ["bar"]
         nodemanager = NodeManager(config, ["popen//chdir=%s" % dest])
         nodemanager.setup_nodes(None)  # calls .rsync_roots()
         assert dest.join("dir1").check()
         assert not dest.join("dir1", "dir2").check()
         assert dest.join("dir5", "file").check()
         assert not dest.join("dir6").check()
-        assert not dest.join('foo').check()
-        assert not dest.join('bar').check()
+        assert not dest.join("foo").check()
+        assert not dest.join("bar").check()
 
     def test_optimise_popen(self, testdir, mysetup, workercontroller):
         source = mysetup.source
         specs = ["popen"] * 3
         source.join("conftest.py").write("rsyncdirs = ['a']")
-        source.ensure('a', dir=1)
+        source.ensure("a", dir=1)
         config = testdir.parseconfig(source)
         nodemanager = NodeManager(config, specs)
         nodemanager.setup_nodes(None)  # calls .rysnc_roots()
@@ -246,12 +259,15 @@ class TestNodeManager:
             assert not gwspec.chdir
 
     def test_ssh_setup_nodes(self, specssh, testdir):
-        testdir.makepyfile(__init__="",
-                           test_x="""
+        testdir.makepyfile(
+            __init__="",
+            test_x="""
             def test_one():
                 pass
-        """)
-        reprec = testdir.inline_run("-d", "--rsyncdir=%s" % testdir.tmpdir,
-                                    "--tx", specssh, testdir.tmpdir)
+        """,
+        )
+        reprec = testdir.inline_run(
+            "-d", "--rsyncdir=%s" % testdir.tmpdir, "--tx", specssh, testdir.tmpdir
+        )
         rep, = reprec.getreports("pytest_runtest_logreport")
         assert rep.passed

tox.ini

@@ -1,11 +1,10 @@
 [tox]
 # if you change the envlist, please update .travis.yml file as well
 envlist=
-  py{27,34,35,36}-pytest{30,31,32,33}
-  py{27,36}-pytest{30,31,32,33}-pexpect
+  linting
+  py{27,34,35,36}-pytest{30,31,32,33,36,38}
+  py{27,36}-pytest36-pexpect
   py{27,36}-pytest{master,features}
-  flakes
-  readme
 
 
 [testenv]
@@ -19,6 +18,8 @@ deps =
   pytest31: pytest~=3.1.0
   pytest32: pytest~=3.2.0
   pytest33: pytest~=3.3.0
+  pytest36: pytest~=3.6.0
+  pytest38: pytest~=3.8.0
   pytestmaster: git+https://github.com/pytest-dev/pytest.git@master
   pytestfeatures: git+https://github.com/pytest-dev/pytest.git@features
   pexpect: pexpect
@@ -27,20 +28,30 @@ platform=
 commands=
   # always clean to avoid code unmarshal mismatch on old python/pytest
   py.cleanup -aq
-  py.test {posargs}
+  pytest {posargs}
 
-[testenv:flakes]
+[testenv:linting]
+skipsdist = True
+usedevelop = True
+deps =
+  pre-commit
+commands = pre-commit run --all-files --show-diff-on-failure
+
+[testenv:release]
 changedir=
-deps = flake8
-commands = flake8 setup.py testing xdist
-
-[testenv:readme]
-changedir =
-deps = readme
-skip_install = true
-commands = python setup.py check -r -s
-
+decription = do a release, required posarg of the version number
+basepython = python3.6
+skipsdist = True
+usedevelop = True
+passenv = *
+deps =
+    towncrier
+commands =
+    towncrier --version {posargs} --yes
 
 [pytest]
 addopts = -rsfxX
-;; hello
+
+[flake8]
+max-line-length = 120
+ignore = E203,W503

xdist/__init__.py

@@ -1,3 +1,3 @@
 from xdist._version import version as __version__
 
-__all__ = ['__version__']
+__all__ = ["__version__"]

xdist/dsession.py

@@ -10,15 +10,15 @@ from xdist.scheduler import (
 )
 
 
-queue = py.builtin._tryimport('queue', 'Queue')
+from six.moves.queue import Empty, Queue
 
 
 class Interrupted(KeyboardInterrupt):
     """ signals an immediate interruption. """
 
 
-class DSession:
-    """A py.test plugin which runs a distributed test session
+class DSession(object):
+    """A pytest plugin which runs a distributed test session
 
     At the beginning of the test session this creates a NodeManager
     instance which creates and starts all nodes.  Nodes then emit
@@ -26,7 +26,7 @@ class DSession:
     methods.
 
     Once a node is started it will automatically start running the
-    py.test mainloop with some custom hooks.  This means a node
+    pytest mainloop with some custom hooks.  This means a node
     automatically starts collecting tests.  Once tests are collected
     it will wait for instructions.
     """
@@ -41,7 +41,7 @@ class DSession:
         self.shuttingdown = False
         self.countfailures = 0
         self.maxfail = config.getvalue("maxfail")
-        self.queue = queue.Queue()
+        self.queue = Queue()
         self._session = None
         self._failed_collection_errors = {}
         self._active_nodes = set()
@@ -84,7 +84,7 @@ class DSession:
 
     def pytest_sessionfinish(self, session):
         """Shutdown all nodes."""
-        nm = getattr(self, 'nodemanager', None)  # if not fully initialized
+        nm = getattr(self, "nodemanager", None)  # if not fully initialized
         if nm is not None:
             nm.teardown_nodes()
         self._session = None
@@ -95,19 +95,18 @@ class DSession:
 
     @pytest.mark.trylast
     def pytest_xdist_make_scheduler(self, config, log):
-        dist = config.getvalue('dist')
+        dist = config.getvalue("dist")
         schedulers = {
-            'each': EachScheduling,
-            'load': LoadScheduling,
-            'loadscope': LoadScopeScheduling,
-            'loadfile': LoadFileScheduling,
+            "each": EachScheduling,
+            "load": LoadScheduling,
+            "loadscope": LoadScopeScheduling,
+            "loadfile": LoadFileScheduling,
         }
         return schedulers[dist](config, log)
 
     def pytest_runtestloop(self):
         self.sched = self.config.hook.pytest_xdist_make_scheduler(
-            config=self.config,
-            log=self.log
+            config=self.config, log=self.log
         )
         assert self.sched is not None
 
@@ -129,7 +128,7 @@ class DSession:
             try:
                 eventcall = self.queue.get(timeout=2.0)
                 break
-            except queue.Empty:
+            except Empty:
                 continue
         callname, kwargs = eventcall
         assert callname, kwargs
@@ -151,8 +150,8 @@ class DSession:
         collection without any further input.
         """
         node.workerinfo = workerinfo
-        node.workerinfo['id'] = node.gateway.id
-        node.workerinfo['spec'] = node.gateway.spec
+        node.workerinfo["id"] = node.gateway.id
+        node.workerinfo["spec"] = node.gateway.spec
 
         # TODO: (#234 task) needs this for pytest. Remove when refactor in pytest repo
         node.slaveinfo = node.workerinfo
@@ -172,7 +171,7 @@ class DSession:
         workerready before shutdown was triggered.
         """
         self.config.hook.pytest_testnodedown(node=node, error=None)
-        if node.workeroutput['exitstatus'] == 2:  # keyboard-interrupt
+        if node.workeroutput["exitstatus"] == 2:  # keyboard-interrupt
             self.shouldstop = "%s received keyboard-interrupt" % (node,)
             self.worker_errordown(node, "keyboard-interrupt")
             return
@@ -193,14 +192,15 @@ class DSession:
                 self.handle_crashitem(crashitem, node)
 
         self._failed_nodes_count += 1
-        maximum_reached = (self._max_worker_restart is not None and
-                           self._failed_nodes_count > self._max_worker_restart)
+        maximum_reached = (
+            self._max_worker_restart is not None
+            and self._failed_nodes_count > self._max_worker_restart
+        )
         if maximum_reached:
             if self._max_worker_restart == 0:
-                msg = 'Worker restarting disabled'
+                msg = "Worker restarting disabled"
             else:
-                msg = "Maximum crashed workers reached: %d" % \
-                      self._max_worker_restart
+                msg = "Maximum crashed workers reached: %d" % self._max_worker_restart
             self.report_line(msg)
         else:
             self.report_line("Replacing crashed worker %s" % node.gateway.id)
@@ -218,8 +218,7 @@ class DSession:
         """
         if self.shuttingdown:
             return
-        self.config.hook.pytest_xdist_node_collection_finished(node=node,
-                                                               ids=ids)
+        self.config.hook.pytest_xdist_node_collection_finished(node=node, ids=ids)
         # tell session which items were effectively collected otherwise
         # the master node will finish the session with EXIT_NOTESTSCOLLECTED
         self._session.testscollected = len(ids)
@@ -230,19 +229,18 @@ class DSession:
             if self.terminal and not self.sched.has_pending:
                 self.trdist.ensure_show_status()
                 self.terminal.write_line("")
-                self.terminal.write_line("scheduling tests via %s" % (
-                    self.sched.__class__.__name__))
+                self.terminal.write_line(
+                    "scheduling tests via %s" % (self.sched.__class__.__name__)
+                )
             self.sched.schedule()
 
     def worker_logstart(self, node, nodeid, location):
         """Emitted when a node calls the pytest_runtest_logstart hook."""
-        self.config.hook.pytest_runtest_logstart(
-            nodeid=nodeid, location=location)
+        self.config.hook.pytest_runtest_logstart(nodeid=nodeid, location=location)
 
     def worker_logfinish(self, node, nodeid, location):
         """Emitted when a node calls the pytest_runtest_logfinish hook."""
-        self.config.hook.pytest_runtest_logfinish(
-            nodeid=nodeid, location=location)
+        self.config.hook.pytest_runtest_logfinish(nodeid=nodeid, location=location)
 
     def worker_testreport(self, node, rep):
         """Emitted when a node calls the pytest_runtest_logreport hook."""
@@ -259,15 +257,24 @@ class DSession:
         self.sched.mark_test_complete(node, item_index, duration)
 
     def worker_collectreport(self, node, rep):
-        """Emitted when a node calls the pytest_collectreport hook."""
-        if rep.failed:
-            self._failed_worker_collectreport(node, rep)
+        """Emitted when a node calls the pytest_collectreport hook.
+
+        Because we only need the report when there's a failure, as optimization
+        we only expect to receive failed reports from workers (#330).
+        """
+        assert rep.failed
+        self._failed_worker_collectreport(node, rep)
 
     def worker_logwarning(self, message, code, nodeid, fslocation):
         """Emitted when a node calls the pytest_logwarning hook."""
         kwargs = dict(message=message, code=code, nodeid=nodeid, fslocation=fslocation)
         self.config.hook.pytest_logwarning.call_historic(kwargs=kwargs)
 
+    def worker_warning_captured(self, warning_message, when, item):
+        """Emitted when a node calls the pytest_logwarning hook."""
+        kwargs = dict(warning_message=warning_message, when=when, item=item)
+        self.config.hook.pytest_warning_captured.call_historic(kwargs=kwargs)
+
     def _clone_node(self, node):
         """Return new node based on an existing one.
 
@@ -295,8 +302,7 @@ class DSession:
         if rep.failed:
             self.countfailures += 1
             if self.maxfail and self.countfailures >= self.maxfail:
-                self.shouldstop = "stopping after %d failures" % (
-                    self.countfailures)
+                self.shouldstop = "stopping after %d failures" % (self.countfailures)
 
     def triggershutdown(self):
         self.log("triggering shutdown")
@@ -310,19 +316,20 @@ class DSession:
         runner = self.config.pluginmanager.getplugin("runner")
         fspath = nodeid.split("::")[0]
         msg = "Worker %r crashed while running %r" % (worker.gateway.id, nodeid)
-        rep = runner.TestReport(nodeid, (fspath, None, fspath),
-                                (), "failed", msg, "???")
+        rep = runner.TestReport(
+            nodeid, (fspath, None, fspath), (), "failed", msg, "???"
+        )
         rep.node = worker
         self.config.hook.pytest_runtest_logreport(report=rep)
 
 
-class TerminalDistReporter:
+class TerminalDistReporter(object):
     def __init__(self, config):
         self.config = config
         self.tr = config.pluginmanager.getplugin("terminalreporter")
         self._status = {}
         self._lastlen = 0
-        self._isatty = getattr(self.tr, 'isatty', self.tr.hasmarkup)
+        self._isatty = getattr(self.tr, "isatty", self.tr.hasmarkup)
 
     def write_line(self, msg):
         self.tr.write_line(msg)
@@ -337,8 +344,7 @@ class TerminalDistReporter:
             self.rewrite(self.getstatus())
 
     def getstatus(self):
-        parts = ["%s %s" % (spec.id, self._status[spec.id])
-                 for spec in self._specs]
+        parts = ["%s %s" % (spec.id, self._status[spec.id]) for spec in self._specs]
         return " / ".join(parts)
 
     def rewrite(self, line, newline=False):
@@ -361,17 +367,17 @@ class TerminalDistReporter:
         if self.config.option.verbose > 0:
             rinfo = gateway._rinfo()
             version = "%s.%s.%s" % rinfo.version_info[:3]
-            self.rewrite("[%s] %s Python %s cwd: %s" % (
-                gateway.id, rinfo.platform, version, rinfo.cwd),
-                newline=True)
+            self.rewrite(
+                "[%s] %s Python %s cwd: %s"
+                % (gateway.id, rinfo.platform, version, rinfo.cwd),
+                newline=True,
+            )
         self.setstatus(gateway.spec, "C")
 
     def pytest_testnodeready(self, node):
         if self.config.option.verbose > 0:
             d = node.workerinfo
-            infoline = "[%s] Python %s" % (
-                d['id'],
-                d['version'].replace('\n', ' -- '),)
+            infoline = "[%s] Python %s" % (d["id"], d["version"].replace("\n", " -- "))
             self.rewrite(infoline, newline=True)
         self.setstatus(node.gateway.spec, "ok")
 

xdist/looponfail.py

@@ -1,34 +1,38 @@
 """
-    Implement -f aka looponfailing for py.test.
+    Implement -f aka looponfailing for pytest.
 
     NOTE that we try to avoid loading and depending on application modules
     within the controlling process (the one that starts repeatedly test
     processes) otherwise changes to source code can crash
     the controlling process which should best never happen.
 """
-
+from __future__ import print_function
 import py
 import pytest
 import sys
+import time
 import execnet
 
 
 def pytest_addoption(parser):
     group = parser.getgroup("xdist", "distributed and subprocess testing")
     group._addoption(
-        '-f', '--looponfail',
-        action="store_true", dest="looponfail", default=False,
+        "-f",
+        "--looponfail",
+        action="store_true",
+        dest="looponfail",
+        default=False,
         help="run tests in subprocess, wait for modified files "
-             "and re-run failing test set until all pass.")
+        "and re-run failing test set until all pass.",
+    )
 
 
 def pytest_cmdline_main(config):
 
     if config.getoption("looponfail"):
-        usepdb = config.getoption('usepdb')  # a core option
+        usepdb = config.getoption("usepdb")  # a core option
         if usepdb:
-            raise pytest.UsageError(
-                "--pdb incompatible with --looponfail.")
+            raise pytest.UsageError("--pdb incompatible with --looponfail.")
         looponfail_main(config)
         return 2  # looponfail only can get stop with ctrl-C anyway
 
@@ -44,8 +48,8 @@ def looponfail_main(config):
                 # the last failures passed, let's immediately rerun all
                 continue
             repr_pytest_looponfailinfo(
-                failreports=remotecontrol.failures,
-                rootdirs=rootdirs)
+                failreports=remotecontrol.failures, rootdirs=rootdirs
+            )
             statrecorder.waitonchange(checkinterval=2.0)
     except KeyboardInterrupt:
         print()
@@ -59,7 +63,7 @@ class RemoteControl(object):
     def trace(self, *args):
         if self.config.option.debug:
             msg = " ".join([str(x) for x in args])
-            py.builtin.print_("RemoteControl:", msg)
+            print("RemoteControl:", msg)
 
     def initgateway(self):
         return execnet.makegateway("popen")
@@ -67,7 +71,7 @@ class RemoteControl(object):
     def setup(self, out=None):
         if out is None:
             out = py.io.TerminalWriter()
-        if hasattr(self, 'gateway'):
+        if hasattr(self, "gateway"):
             raise ValueError("already have gateway %r" % self.gateway)
         self.trace("setting up worker session")
         self.gateway = self.initgateway()
@@ -81,15 +85,16 @@ class RemoteControl(object):
         def write(s):
             out._file.write(s)
             out._file.flush()
+
         remote_outchannel.setcallback(write)
 
     def ensure_teardown(self):
-        if hasattr(self, 'channel'):
+        if hasattr(self, "channel"):
             if not self.channel.isclosed():
                 self.trace("closing", self.channel)
                 self.channel.close()
             del self.channel
-        if hasattr(self, 'gateway'):
+        if hasattr(self, "gateway"):
             self.trace("exiting", self.gateway)
             self.gateway.exit()
             del self.gateway
@@ -137,8 +142,9 @@ def repr_pytest_looponfailinfo(failreports, rootdirs):
 def init_worker_session(channel, args, option_dict):
     import os
     import sys
+
     outchannel = channel.gateway.newchannel()
-    sys.stdout = sys.stderr = outchannel.makefile('w')
+    sys.stdout = sys.stderr = outchannel.makefile("w")
     channel.send(outchannel)
     # prune sys.path to not contain relative paths
     newpaths = []
@@ -151,13 +157,15 @@ def init_worker_session(channel, args, option_dict):
 
     # fullwidth, hasmarkup = channel.receive()
     from _pytest.config import Config
+
     config = Config.fromdictargs(option_dict, list(args))
     config.args = args
     from xdist.looponfail import WorkerFailSession
+
     WorkerFailSession(config, channel).main()
 
 
-class WorkerFailSession:
+class WorkerFailSession(object):
     def __init__(self, config, channel):
         self.config = config
         self.channel = channel
@@ -180,7 +188,8 @@ class WorkerFailSession:
         except pytest.UsageError:
             items = session.perform_collect(None)
         hook.pytest_collection_modifyitems(
-            session=session, config=session.config, items=items)
+            session=session, config=session.config, items=items
+        )
         hook.pytest_collection_finish(session=session)
         return True
 
@@ -206,12 +215,12 @@ class WorkerFailSession:
         for rep in self.recorded_failures:
             trails.append(rep.nodeid)
             loc = rep.longrepr
-            loc = str(getattr(loc, 'reprcrash', loc))
+            loc = str(getattr(loc, "reprcrash", loc))
             failreports.append(loc)
         self.channel.send((trails, failreports, self.collection_failed))
 
 
-class StatRecorder:
+class StatRecorder(object):
     def __init__(self, rootdirlist):
         self.rootdirlist = rootdirlist
         self.statcache = {}
@@ -228,7 +237,7 @@ class StatRecorder:
             changed = self.check()
             if changed:
                 return
-            py.std.time.sleep(checkinterval)
+            time.sleep(checkinterval)
 
     def check(self, removepycfiles=True):  # noqa, too complex
         changed = False
@@ -244,10 +253,12 @@ class StatRecorder:
                         changed = True
                 else:
                     if oldstat:
-                        if oldstat.mtime != curstat.mtime or \
-                           oldstat.size != curstat.size:
+                        if (
+                            oldstat.mtime != curstat.mtime
+                            or oldstat.size != curstat.size
+                        ):
                             changed = True
-                            py.builtin.print_("# MODIFIED", path)
+                            print("# MODIFIED", path)
                             if removepycfiles and path.ext == ".py":
                                 pycfile = path + "c"
                                 if pycfile.check():

xdist/plugin.py

@@ -1,18 +1,35 @@
+import os
+
 import py
 import pytest
 
 
-def parse_numprocesses(s):
-    if s == 'auto':
+def auto_detect_cpus():
+    try:
+        from os import sched_getaffinity
+    except ImportError:
+        if os.environ.get("TRAVIS") == "true":
+            # workaround https://bitbucket.org/pypy/pypy/issues/2375
+            return 2
         try:
             from os import cpu_count
         except ImportError:
             from multiprocessing import cpu_count
-        try:
-            n = cpu_count()
-        except NotImplementedError:
-            return 1
-        return n if n else 1
+    else:
+
+        def cpu_count():
+            return len(sched_getaffinity(0))
+
+    try:
+        n = cpu_count()
+    except NotImplementedError:
+        return 1
+    return n if n else 1
+
+
+def parse_numprocesses(s):
+    if s == "auto":
+        return auto_detect_cpus()
     else:
         return int(s)
 
@@ -20,60 +37,101 @@ def parse_numprocesses(s):
 def pytest_addoption(parser):
     group = parser.getgroup("xdist", "distributed and subprocess testing")
     group._addoption(
-        '-n', '--numprocesses', dest="numprocesses", metavar="numprocesses",
+        "-n",
+        "--numprocesses",
+        dest="numprocesses",
+        metavar="numprocesses",
         action="store",
         type=parse_numprocesses,
         help="shortcut for '--dist=load --tx=NUM*popen', "
-             "you can use 'auto' here for auto detection CPUs number on "
-             "host system")
-    group.addoption('--max-worker-restart', '--max-slave-restart', action="store", default=None,
-                    dest="maxworkerrestart",
-                    help="maximum number of workers that can be restarted "
-                         "when crashed (set to zero to disable this feature)\n"
-                         "'--max-slave-restart' option is deprecated and will be removed in "
-                         "a future release")
+        "you can use 'auto' here for auto detection CPUs number on "
+        "host system",
+    )
     group.addoption(
-        '--dist', metavar="distmode",
-        action="store", choices=['each', 'load', 'loadscope', 'loadfile', 'no'],
-        dest="dist", default="no",
-        help=("set mode for distributing tests to exec environments.\n\n"
-              "each: send each test to all available environments.\n\n"
-              "load: load balance by sending any pending test to any"
-              " available environment.\n\n"
-              "loadscope: load balance by sending pending groups of tests in"
-              " the same scope to any available environment.\n\n"
-              "loadfile: load balance by sending test grouped by file"
-              " to any available environment.\n\n"
-              "(default) no: run tests inprocess, don't distribute."))
+        "--max-worker-restart",
+        "--max-slave-restart",
+        action="store",
+        default=None,
+        dest="maxworkerrestart",
+        help="maximum number of workers that can be restarted "
+        "when crashed (set to zero to disable this feature)\n"
+        "'--max-slave-restart' option is deprecated and will be removed in "
+        "a future release",
+    )
     group.addoption(
-        '--tx', dest="tx", action="append", default=[],
+        "--dist",
+        metavar="distmode",
+        action="store",
+        choices=["each", "load", "loadscope", "loadfile", "no"],
+        dest="dist",
+        default="no",
+        help=(
+            "set mode for distributing tests to exec environments.\n\n"
+            "each: send each test to all available environments.\n\n"
+            "load: load balance by sending any pending test to any"
+            " available environment.\n\n"
+            "loadscope: load balance by sending pending groups of tests in"
+            " the same scope to any available environment.\n\n"
+            "loadfile: load balance by sending test grouped by file"
+            " to any available environment.\n\n"
+            "(default) no: run tests inprocess, don't distribute."
+        ),
+    )
+    group.addoption(
+        "--tx",
+        dest="tx",
+        action="append",
+        default=[],
         metavar="xspec",
-        help=("add a test execution environment. some examples: "
-              "--tx popen//python=python2.5 --tx socket=192.168.1.102:8888 "
-              "--tx ssh=user@codespeak.net//chdir=testcache"))
+        help=(
+            "add a test execution environment. some examples: "
+            "--tx popen//python=python2.5 --tx socket=192.168.1.102:8888 "
+            "--tx ssh=user@codespeak.net//chdir=testcache"
+        ),
+    )
     group._addoption(
-        '-d',
-        action="store_true", dest="distload", default=False,
-        help="load-balance tests.  shortcut for '--dist=load'")
+        "-d",
+        action="store_true",
+        dest="distload",
+        default=False,
+        help="load-balance tests.  shortcut for '--dist=load'",
+    )
     group.addoption(
-        '--rsyncdir', action="append", default=[], metavar="DIR",
-        help="add directory for rsyncing to remote tx nodes.")
+        "--rsyncdir",
+        action="append",
+        default=[],
+        metavar="DIR",
+        help="add directory for rsyncing to remote tx nodes.",
+    )
     group.addoption(
-        '--rsyncignore', action="append", default=[], metavar="GLOB",
-        help="add expression for ignores when rsyncing to remote tx nodes.")
+        "--rsyncignore",
+        action="append",
+        default=[],
+        metavar="GLOB",
+        help="add expression for ignores when rsyncing to remote tx nodes.",
+    )
 
     group.addoption(
-        "--boxed", action="store_true",
-        help="backward compatibility alias for pytest-forked --forked")
+        "--boxed",
+        action="store_true",
+        help="backward compatibility alias for pytest-forked --forked",
+    )
     parser.addini(
-        'rsyncdirs', 'list of (relative) paths to be rsynced for'
-        ' remote distributed testing.', type="pathlist")
+        "rsyncdirs",
+        "list of (relative) paths to be rsynced for" " remote distributed testing.",
+        type="pathlist",
+    )
     parser.addini(
-        'rsyncignore', 'list of (relative) glob-style paths to be ignored '
-        'for rsyncing.', type="pathlist")
+        "rsyncignore",
+        "list of (relative) glob-style paths to be ignored " "for rsyncing.",
+        type="pathlist",
+    )
     parser.addini(
-        "looponfailroots", type="pathlist",
-        help="directories to check for changes", default=[py.path.local()])
+        "looponfailroots",
+        type="pathlist",
+        help="directories to check for changes",
+        default=[py.path.local()],
+    )
 
 
 # -------------------------------------------------------------------------
@@ -83,12 +141,14 @@ def pytest_addoption(parser):
 
 def pytest_addhooks(pluginmanager):
     from xdist import newhooks
+
     # avoid warnings with pytest-2.8
     method = getattr(pluginmanager, "add_hookspecs", None)
     if method is None:
         method = pluginmanager.addhooks
     method(newhooks)
 
+
 # -------------------------------------------------------------------------
 # distributed testing initialization
 # -------------------------------------------------------------------------
@@ -98,6 +158,7 @@ def pytest_addhooks(pluginmanager):
 def pytest_configure(config):
     if config.getoption("dist") != "no" and not config.getvalue("collectonly"):
         from xdist.dsession import DSession
+
         session = DSession(config)
         config.pluginmanager.register(session, "dsession")
         tr = config.pluginmanager.getplugin("terminalreporter")
@@ -109,18 +170,20 @@ def pytest_configure(config):
 @pytest.mark.tryfirst
 def pytest_cmdline_main(config):
     if config.option.numprocesses:
-        if config.option.dist == 'no':
+        if config.option.dist == "no":
             config.option.dist = "load"
-        config.option.tx = ['popen'] * config.option.numprocesses
+        config.option.tx = ["popen"] * config.option.numprocesses
     if config.option.distload:
         config.option.dist = "load"
     val = config.getvalue
     if not val("collectonly"):
-        usepdb = config.getoption('usepdb')  # a core option
+        usepdb = config.getoption("usepdb")  # a core option
         if val("dist") != "no":
             if usepdb:
                 raise pytest.UsageError(
-                    "--pdb is incompatible with distributing tests; try using -n0.")  # noqa: E501
+                    "--pdb is incompatible with distributing tests; try using -n0."
+                )  # noqa: E501
+
 
 # -------------------------------------------------------------------------
 # fixtures
@@ -132,7 +195,7 @@ def worker_id(request):
     """Return the id of the current worker ('gw0', 'gw1', etc) or 'master'
     if running on the master node.
     """
-    if hasattr(request.config, 'workerinput'):
-        return request.config.workerinput['workerid']
+    if hasattr(request.config, "workerinput"):
+        return request.config.workerinput["workerid"]
     else:
-        return 'master'
+        return "master"

xdist/remote.py

@@ -14,10 +14,10 @@ import _pytest.hookspec
 import pytest
 
 
-class WorkerInteractor:
+class WorkerInteractor(object):
     def __init__(self, config, channel):
         self.config = config
-        self.workerid = config.workerinput.get('workerid', "?")
+        self.workerid = config.workerinput.get("workerid", "?")
         self.log = py.log.Producer("worker-%s" % self.workerid)
         if not config.option.debug:
             py.log.setconsumer(self.log._keywords, None)
@@ -39,7 +39,7 @@ class WorkerInteractor:
 
     @pytest.hookimpl(hookwrapper=True)
     def pytest_sessionfinish(self, exitstatus):
-        self.config.workeroutput['exitstatus'] = exitstatus
+        self.config.workeroutput["exitstatus"] = exitstatus
         yield
         self.sendevent("workerfinished", workeroutput=self.config.workeroutput)
 
@@ -56,7 +56,7 @@ class WorkerInteractor:
                 return True
             self.log("received command", name, kwargs)
             if name == "runtests":
-                torun.extend(kwargs['indices'])
+                torun.extend(kwargs["indices"])
             elif name == "runtests_all":
                 torun.extend(range(len(session.items)))
             self.log("items to run:", torun)
@@ -79,24 +79,25 @@ class WorkerInteractor:
             nextitem = None
 
         start = time.time()
-        self.config.hook.pytest_runtest_protocol(
-            item=item,
-            nextitem=nextitem)
+        self.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
         duration = time.time() - start
-        self.sendevent("runtest_protocol_complete", item_index=self.item_index,
-                       duration=duration)
+        self.sendevent(
+            "runtest_protocol_complete", item_index=self.item_index, duration=duration
+        )
 
     def pytest_collection_finish(self, session):
         self.sendevent(
             "collectionfinish",
             topdir=str(session.fspath),
-            ids=[item.nodeid for item in session.items])
+            ids=[item.nodeid for item in session.items],
+        )
 
     def pytest_runtest_logstart(self, nodeid, location):
         self.sendevent("logstart", nodeid=nodeid, location=location)
 
     # the pytest_runtest_logfinish hook was introduced in pytest 3.4
-    if hasattr(_pytest.hookspec, 'pytest_runtest_logfinish'):
+    if hasattr(_pytest.hookspec, "pytest_runtest_logfinish"):
+
         def pytest_runtest_logfinish(self, nodeid, location):
             self.sendevent("logfinish", nodeid=nodeid, location=location)
 
@@ -108,12 +109,31 @@ class WorkerInteractor:
         self.sendevent("testreport", data=data)
 
     def pytest_collectreport(self, report):
-        data = serialize_report(report)
-        self.sendevent("collectreport", data=data)
+        # master only needs reports that failed, as optimization send only them instead (#330)
+        if report.failed:
+            data = serialize_report(report)
+            self.sendevent("collectreport", data=data)
 
     def pytest_logwarning(self, message, code, nodeid, fslocation):
-        self.sendevent("logwarning", message=message, code=code, nodeid=nodeid,
-                       fslocation=str(fslocation))
+        self.sendevent(
+            "logwarning",
+            message=message,
+            code=code,
+            nodeid=nodeid,
+            fslocation=str(fslocation),
+        )
+
+    # the pytest_warning_captured hook was introduced in pytest 3.8
+    if hasattr(_pytest.hookspec, "pytest_warning_captured"):
+
+        def pytest_warning_captured(self, warning_message, when, item):
+            self.sendevent(
+                "warning_captured",
+                warning_message_data=serialize_warning_message(warning_message),
+                when=when,
+                # item cannot be serialized and will always be None when used with xdist
+                item=None,
+            )
 
 
 def serialize_report(rep):
@@ -122,34 +142,33 @@ def serialize_report(rep):
         reprcrash = rep.longrepr.reprcrash.__dict__.copy()
 
         new_entries = []
-        for entry in reprtraceback['reprentries']:
-            entry_data = {
-                'type': type(entry).__name__,
-                'data': entry.__dict__.copy(),
-            }
-            for key, value in entry_data['data'].items():
-                if hasattr(value, '__dict__'):
-                    entry_data['data'][key] = value.__dict__.copy()
+        for entry in reprtraceback["reprentries"]:
+            entry_data = {"type": type(entry).__name__, "data": entry.__dict__.copy()}
+            for key, value in entry_data["data"].items():
+                if hasattr(value, "__dict__"):
+                    entry_data["data"][key] = value.__dict__.copy()
             new_entries.append(entry_data)
 
-        reprtraceback['reprentries'] = new_entries
+        reprtraceback["reprentries"] = new_entries
 
         return {
-            'reprcrash': reprcrash,
-            'reprtraceback': reprtraceback,
-            'sections': rep.longrepr.sections
+            "reprcrash": reprcrash,
+            "reprtraceback": reprtraceback,
+            "sections": rep.longrepr.sections,
         }
 
     import py
+
     d = rep.__dict__.copy()
-    if hasattr(rep.longrepr, 'toterminal'):
-        if hasattr(rep.longrepr, 'reprtraceback') \
-                and hasattr(rep.longrepr, 'reprcrash'):
-            d['longrepr'] = disassembled_report(rep)
+    if hasattr(rep.longrepr, "toterminal"):
+        if hasattr(rep.longrepr, "reprtraceback") and hasattr(
+            rep.longrepr, "reprcrash"
+        ):
+            d["longrepr"] = disassembled_report(rep)
         else:
-            d['longrepr'] = str(rep.longrepr)
+            d["longrepr"] = str(rep.longrepr)
     else:
-        d['longrepr'] = rep.longrepr
+        d["longrepr"] = rep.longrepr
     for name in d:
         if isinstance(d[name], py.path.local):
             d[name] = str(d[name])
@@ -158,8 +177,43 @@ def serialize_report(rep):
     return d
 
 
+def serialize_warning_message(warning_message):
+    if isinstance(warning_message.message, Warning):
+        message_module = type(warning_message.message).__module__
+        message_class_name = type(warning_message.message).__name__
+        message_args = warning_message.message.args
+        message_str = None
+    else:
+        message_str = warning_message.message
+        message_module = None
+        message_class_name = None
+        message_args = None
+    if warning_message.category:
+        category_module = warning_message.category.__module__
+        category_class_name = warning_message.category.__name__
+    else:
+        category_module = None
+        category_class_name = None
+
+    result = {
+        "message_str": message_str,
+        "message_module": message_module,
+        "message_class_name": message_class_name,
+        "message_args": message_args,
+        "category_module": category_module,
+        "category_class_name": category_class_name,
+    }
+    # access private _WARNING_DETAILS because the attributes vary between Python versions
+    for attr_name in warning_message._WARNING_DETAILS:
+        if attr_name in ("message", "category"):
+            continue
+        result[attr_name] = getattr(warning_message, attr_name)
+    return result
+
+
 def getinfodict():
     import platform
+
     return dict(
         version=sys.version,
         version_info=tuple(sys.version_info),
@@ -172,7 +226,8 @@ def getinfodict():
 
 def remote_initconfig(option_dict, args):
     from _pytest.config import Config
-    option_dict['plugins'].append("no:terminal")
+
+    option_dict["plugins"].append("no:terminal")
     config = Config.fromdictargs(option_dict, args)
     config.option.looponfail = False
     config.option.usepdb = False
@@ -183,18 +238,19 @@ def remote_initconfig(option_dict, args):
     return config
 
 
-if __name__ == '__channelexec__':
+if __name__ == "__channelexec__":
     channel = channel  # noqa
     workerinput, args, option_dict = channel.receive()
     importpath = os.getcwd()
     sys.path.insert(0, importpath)  # XXX only for remote situations
-    os.environ['PYTHONPATH'] = (
-        importpath + os.pathsep +
-        os.environ.get('PYTHONPATH', ''))
-    os.environ['PYTEST_XDIST_WORKER'] = workerinput['workerid']
-    os.environ['PYTEST_XDIST_WORKER_COUNT'] = str(workerinput['workercount'])
+    os.environ["PYTHONPATH"] = (
+        importpath + os.pathsep + os.environ.get("PYTHONPATH", "")
+    )
+    os.environ["PYTEST_XDIST_WORKER"] = workerinput["workerid"]
+    os.environ["PYTEST_XDIST_WORKER_COUNT"] = str(workerinput["workercount"])
     # os.environ['PYTHONPATH'] = importpath
     import py
+
     config = remote_initconfig(option_dict, args)
     config.workerinput = workerinput
     config.workeroutput = {}

xdist/report.py

@@ -1,4 +1,4 @@
-import py
+from __future__ import print_function
 from difflib import unified_diff
 
 
@@ -11,16 +11,11 @@ def report_collection_diff(from_collection, to_collection, from_id, to_id):
     if from_collection == to_collection:
         return None
 
-    diff = unified_diff(
-        from_collection,
-        to_collection,
-        fromfile=from_id,
-        tofile=to_id,
-    )
-    error_message = py.builtin._totext(
-        'Different tests were collected between {from_id} and {to_id}. '
-        'The difference is:\n'
-        '{diff}'
-    ).format(from_id=from_id, to_id=to_id, diff='\n'.join(diff))
+    diff = unified_diff(from_collection, to_collection, fromfile=from_id, tofile=to_id)
+    error_message = (
+        u"Different tests were collected between {from_id} and {to_id}. "
+        u"The difference is:\n"
+        u"{diff}"
+    ).format(from_id=from_id, to_id=to_id, diff="\n".join(diff))
     msg = "\n".join([x.rstrip() for x in error_message.split("\n")])
     return msg

xdist/scheduler/each.py

@@ -4,7 +4,7 @@ from xdist.workermanage import parse_spec_config
 from xdist.report import report_collection_diff
 
 
-class EachScheduling:
+class EachScheduling(object):
     """Implement scheduling of test items on all nodes
 
     If a node gets added after the test run is started then it is
@@ -86,10 +86,12 @@ class EachScheduling:
                 if deadnode.gateway.spec == node.gateway.spec:
                     dead_collection = self.node2collection[deadnode]
                     if collection != dead_collection:
-                        msg = report_collection_diff(dead_collection,
-                                                     collection,
-                                                     deadnode.gateway.id,
-                                                     node.gateway.id)
+                        msg = report_collection_diff(
+                            dead_collection,
+                            collection,
+                            deadnode.gateway.id,
+                            node.gateway.id,
+                        )
                         self.log(msg)
                         return
                     pending = self._removed2pending.pop(deadnode)

xdist/scheduler/filescope.py

@@ -20,10 +20,10 @@ class LoadFileScheduling(LoadScopeScheduling):
     This class behaves very much like LoadScopeScheduling, but with a file-level scope.
     """
 
-    def __init(self, config, log=None):
+    def __init__(self, config, log=None):
         super(LoadFileScheduling, self).__init__(config, log)
         if log is None:
-            self.log = Producer('loadfilesched')
+            self.log = Producer("loadfilesched")
         else:
             self.log = log.loadfilesched
 
@@ -49,4 +49,4 @@ class LoadFileScheduling(LoadScopeScheduling):
             example/loadsuite/test/test_delta.py
             example/loadsuite/epsilon/__init__.py
         """
-        return nodeid.split('::', 1)[0]
+        return nodeid.split("::", 1)[0]

xdist/scheduler/load.py

@@ -7,7 +7,7 @@ from xdist.workermanage import parse_spec_config
 from xdist.report import report_collection_diff
 
 
-class LoadScheduling:
+class LoadScheduling(object):
     """Implement load scheduling across nodes.
 
     This distributes the tests collected across all nodes so each test
@@ -133,10 +133,9 @@ class LoadScheduling:
             assert self.collection
             if collection != self.collection:
                 other_node = next(iter(self.node2collection.keys()))
-                msg = report_collection_diff(self.collection,
-                                             collection,
-                                             other_node.gateway.id,
-                                             node.gateway.id)
+                msg = report_collection_diff(
+                    self.collection, collection, other_node.gateway.id, node.gateway.id
+                )
                 self.log(msg)
                 return
         self.node2collection[node] = list(collection)
@@ -226,7 +225,7 @@ class LoadScheduling:
 
         # XXX allow nodes to have different collections
         if not self._check_nodes_have_same_collection():
-            self.log('**Different tests collected, aborting run**')
+            self.log("**Different tests collected, aborting run**")
             return
 
         # Collections are identical, create the index of pending items.
@@ -238,8 +237,7 @@ class LoadScheduling:
         # Send a batch of tests to run. If we don't have at least two
         # tests per node, we have to send them all so that we can send
         # shutdown signals and get all nodes working.
-        initial_batch = max(len(self.pending) // 4,
-                            2 * len(self.nodes))
+        initial_batch = max(len(self.pending) // 4, 2 * len(self.nodes))
 
         # distribute tests round-robin up to the batch size
         # (or until we run out)
@@ -271,18 +269,15 @@ class LoadScheduling:
         same_collection = True
         for node, collection in node_collection_items[1:]:
             msg = report_collection_diff(
-                col,
-                collection,
-                first_node.gateway.id,
-                node.gateway.id,
+                col, collection, first_node.gateway.id, node.gateway.id
             )
             if msg:
                 same_collection = False
                 self.log(msg)
                 if self.config is not None:
                     rep = CollectReport(
-                        node.gateway.id, 'failed',
-                        longrepr=msg, result=[])
+                        node.gateway.id, "failed", longrepr=msg, result=[]
+                    )
                     self.config.hook.pytest_collectreport(report=rep)
 
         return same_collection

xdist/scheduler/loadscope.py

@@ -6,7 +6,7 @@ from xdist.report import report_collection_diff
 from xdist.workermanage import parse_spec_config
 
 
-class LoadScopeScheduling:
+class LoadScopeScheduling(object):
     """Implement load scheduling across nodes, but grouping test by scope.
 
     This distributes the tests collected across all nodes so each test is run
@@ -93,7 +93,7 @@ class LoadScopeScheduling:
         self.registered_collections = OrderedDict()
 
         if log is None:
-            self.log = Producer('loadscopesched')
+            self.log = Producer("loadscopesched")
         else:
             self.log = log.loadscopesched
 
@@ -187,8 +187,7 @@ class LoadScopeScheduling:
             break
         else:
             raise RuntimeError(
-                'Unable to identify crashitem on a workload with '
-                'pending items'
+                "Unable to identify crashitem on a workload with " "pending items"
             )
 
         # Made uncompleted work unit available again
@@ -224,10 +223,7 @@ class LoadScopeScheduling:
                 other_node = next(iter(self.registered_collections.keys()))
 
                 msg = report_collection_diff(
-                    self.collection,
-                    collection,
-                    other_node.gateway.id,
-                    node.gateway.id
+                    self.collection, collection, other_node.gateway.id, node.gateway.id
                 )
                 self.log(msg)
                 return
@@ -255,9 +251,7 @@ class LoadScopeScheduling:
         scope, work_unit = self.workqueue.popitem(last=False)
 
         # Keep track of the assigned work
-        assigned_to_node = self.assigned_work.setdefault(
-            node, default=OrderedDict()
-        )
+        assigned_to_node = self.assigned_work.setdefault(node, default=OrderedDict())
         assigned_to_node[scope] = work_unit
 
         # Ask the node to execute the workload
@@ -292,14 +286,11 @@ class LoadScopeScheduling:
             example/loadsuite/test/test_delta.py::Delta1
             example/loadsuite/epsilon/__init__.py
         """
-        return nodeid.rsplit('::', 1)[0]
+        return nodeid.rsplit("::", 1)[0]
 
     def _pending_of(self, workload):
         """Return the number of pending tests in a workload."""
-        pending = sum(
-            list(scope.values()).count(False)
-            for scope in workload.values()
-        )
+        pending = sum(list(scope.values()).count(False) for scope in workload.values())
         return pending
 
     def _reschedule(self, node):
@@ -317,7 +308,7 @@ class LoadScopeScheduling:
         if not self.workqueue:
             return
 
-        self.log('Number of units waiting for node:', len(self.workqueue))
+        self.log("Number of units waiting for node:", len(self.workqueue))
 
         # Check that the node is almost depleted of work
         # 2: Heuristic of minimum tests to enqueue more work
@@ -348,13 +339,11 @@ class LoadScopeScheduling:
 
         # Check that all nodes collected the same tests
         if not self._check_nodes_have_same_collection():
-            self.log('**Different tests collected, aborting run**')
+            self.log("**Different tests collected, aborting run**")
             return
 
         # Collections are identical, create the final list of items
-        self.collection = list(
-            next(iter(self.registered_collections.values()))
-        )
+        self.collection = list(next(iter(self.registered_collections.values())))
         if not self.collection:
             return
 
@@ -368,12 +357,12 @@ class LoadScopeScheduling:
         extra_nodes = len(self.nodes) - len(self.workqueue)
 
         if extra_nodes > 0:
-            self.log('Shuting down {0} nodes'.format(extra_nodes))
+            self.log("Shuting down {0} nodes".format(extra_nodes))
 
             for _ in range(extra_nodes):
                 unused_node, assigned = self.assigned_work.popitem(last=True)
 
-                self.log('Shuting down unused node {0}'.format(unused_node))
+                self.log("Shuting down unused node {0}".format(unused_node))
                 unused_node.shutdown()
 
         # Assign initial workload
@@ -402,10 +391,7 @@ class LoadScopeScheduling:
 
         for node, collection in node_collection_items[1:]:
             msg = report_collection_diff(
-                col,
-                collection,
-                first_node.gateway.id,
-                node.gateway.id,
+                col, collection, first_node.gateway.id, node.gateway.id
             )
             if not msg:
                 continue
@@ -416,12 +402,7 @@ class LoadScopeScheduling:
             if self.config is None:
                 continue
 
-            rep = CollectReport(
-                node.gateway.id,
-                'failed',
-                longrepr=msg,
-                result=[]
-            )
+            rep = CollectReport(node.gateway.id, "failed", longrepr=msg, result=[])
             self.config.hook.pytest_collectreport(report=rep)
 
         return same_collection

xdist/workermanage.py

@@ -1,10 +1,13 @@
+from __future__ import print_function
 import fnmatch
 import os
 import re
+import threading
 
 import py
 import pytest
 import execnet
+
 import xdist.remote
 
 from _pytest import runner  # XXX load dynamically
@@ -19,20 +22,21 @@ def parse_spec_config(config):
         except ValueError:
             xspeclist.append(xspec)
         else:
-            xspeclist.extend([xspec[i + 1:]] * num)
+            xspeclist.extend([xspec[i + 1 :]] * num)
     if not xspeclist:
         raise pytest.UsageError(
-            "MISSING test execution (tx) nodes: please specify --tx")
+            "MISSING test execution (tx) nodes: please specify --tx"
+        )
     return xspeclist
 
 
 class NodeManager(object):
     EXIT_TIMEOUT = 10
-    DEFAULT_IGNORES = ['.*', '*.pyc', '*.pyo', '*~']
+    DEFAULT_IGNORES = [".*", "*.pyc", "*.pyo", "*~"]
 
     def __init__(self, config, specs=None, defaultchdir="pyexecnetcache"):
         self.config = config
-        self._nodesready = py.std.threading.Event()
+        self._nodesready = threading.Event()
         self.trace = self.config.trace.get("nodemanager")
         self.group = execnet.Group()
         if specs is None:
@@ -47,7 +51,7 @@ class NodeManager(object):
             self.specs.append(spec)
         self.roots = self._getrsyncdirs()
         self.rsyncoptions = self._getrsyncoptions()
-        self._rsynced_specs = py.builtin.set()
+        self._rsynced_specs = set()
 
     def rsync_roots(self, gateway):
         """Rsync the set of roots to the node's gateway cwd."""
@@ -56,8 +60,7 @@ class NodeManager(object):
                 self.rsync(gateway, root, **self.rsyncoptions)
 
     def setup_nodes(self, putevent):
-        self.config.hook.pytest_xdist_setupnodes(config=self.config,
-                                                 specs=self.specs)
+        self.config.hook.pytest_xdist_setupnodes(config=self.config, specs=self.specs)
         self.trace("setting up nodes")
         nodes = []
         for spec in self.specs:
@@ -69,7 +72,7 @@ class NodeManager(object):
         self.config.hook.pytest_xdist_newgateway(gateway=gw)
         self.rsync_roots(gw)
         node = WorkerController(self, gw, self.config, putevent)
-        gw.node = node          # keep the node alive
+        gw.node = node  # keep the node alive
         node.setup()
         self.trace("started node %r" % node)
         return node
@@ -88,6 +91,7 @@ class NodeManager(object):
             return []
         import pytest
         import _pytest
+
         pytestpath = pytest.__file__.rstrip("co")
         pytestdir = py.path.local(_pytest.__file__).dirpath()
         config = self.config
@@ -111,10 +115,7 @@ class NodeManager(object):
         ignores += self.config.option.rsyncignore
         ignores += self.config.getini("rsyncignore")
 
-        return {
-            'ignores': ignores,
-            'verbose': self.config.option.verbose,
-        }
+        return {"ignores": ignores, "verbose": self.config.option.verbose}
 
     def rsync(self, gateway, source, notify=None, verbose=False, ignores=None):
         """Perform rsync to remote hosts for node."""
@@ -126,9 +127,12 @@ class NodeManager(object):
         if spec.popen and not spec.chdir:
             # XXX This assumes that sources are python-packages
             #     and that adding the basedir does not hurt.
-            gateway.remote_exec("""
+            gateway.remote_exec(
+                """
                 import sys ; sys.path.insert(0, %r)
-            """ % os.path.dirname(str(source))).waitclose()
+            """
+                % os.path.dirname(str(source))
+            ).waitclose()
             return
         if (spec, source) in self._rsynced_specs:
             return
@@ -136,28 +140,24 @@ class NodeManager(object):
         def finished():
             if notify:
                 notify("rsyncrootready", spec, source)
+
         rsync.add_target_host(gateway, finished=finished)
         self._rsynced_specs.add((spec, source))
-        self.config.hook.pytest_xdist_rsyncstart(
-            source=source,
-            gateways=[gateway],
-        )
+        self.config.hook.pytest_xdist_rsyncstart(source=source, gateways=[gateway])
         rsync.send()
-        self.config.hook.pytest_xdist_rsyncfinish(
-            source=source,
-            gateways=[gateway],
-        )
+        self.config.hook.pytest_xdist_rsyncfinish(source=source, gateways=[gateway])
 
 
 class HostRSync(execnet.RSync):
     """ RSyncer that filters out common files
     """
+
     def __init__(self, sourcedir, *args, **kwargs):
         self._synced = {}
         self._ignores = []
-        ignores = kwargs.pop('ignores', None) or []
+        ignores = kwargs.pop("ignores", None) or []
         for x in ignores:
-            x = getattr(x, 'strpath', x)
+            x = getattr(x, "strpath", x)
             self._ignores.append(re.compile(fnmatch.translate(x)))
         super(HostRSync, self).__init__(sourcedir=sourcedir, **kwargs)
 
@@ -171,20 +171,19 @@ class HostRSync(execnet.RSync):
 
     def add_target_host(self, gateway, finished=None):
         remotepath = os.path.basename(self._sourcedir)
-        super(HostRSync, self).add_target(gateway, remotepath,
-                                          finishedcallback=finished,
-                                          delete=True,)
+        super(HostRSync, self).add_target(
+            gateway, remotepath, finishedcallback=finished, delete=True
+        )
 
     def _report_send_file(self, gateway, modified_rel_path):
         if self._verbose:
             path = os.path.basename(self._sourcedir) + "/" + modified_rel_path
             remotepath = gateway.spec.chdir
-            py.builtin.print_('%s:%s <= %s' %
-                              (gateway.spec, remotepath, path))
+            print("%s:%s <= %s" % (gateway.spec, remotepath, path))
 
 
 def make_reltoroot(roots, args):
-    # XXX introduce/use public API for splitting py.test args
+    # XXX introduce/use public API for splitting pytest args
     splitcode = "::"
     result = []
     for arg in args:
@@ -209,11 +208,12 @@ class WorkerController(object):
         self.putevent = putevent
         self.gateway = gateway
         self.config = config
-        self.workerinput = {'workerid': gateway.id,
-                            'workercount': len(nodemanager.specs),
-                            'slaveid': gateway.id,
-                            'slavecount': len(nodemanager.specs)
-                            }
+        self.workerinput = {
+            "workerid": gateway.id,
+            "workercount": len(nodemanager.specs),
+            "slaveid": gateway.id,
+            "slavecount": len(nodemanager.specs),
+        }
         # TODO: deprecated name, backward compatibility only. Remove it in future
         self.slaveinput = self.workerinput
         self._down = False
@@ -223,7 +223,7 @@ class WorkerController(object):
             py.log.setconsumer(self.log._keywords, None)
 
     def __repr__(self):
-        return "<%s %s>" % (self.__class__.__name__, self.gateway.id,)
+        return "<%s %s>" % (self.__class__.__name__, self.gateway.id)
 
     @property
     def shutting_down(self):
@@ -238,24 +238,22 @@ class WorkerController(object):
         option_dict = vars(self.config.option)
         if spec.popen:
             name = "popen-%s" % self.gateway.id
-            if hasattr(self.config, '_tmpdirhandler'):
+            if hasattr(self.config, "_tmpdirhandler"):
                 basetemp = self.config._tmpdirhandler.getbasetemp()
-                option_dict['basetemp'] = str(basetemp.join(name))
+                option_dict["basetemp"] = str(basetemp.join(name))
         self.config.hook.pytest_configure_node(node=self)
         self.channel = self.gateway.remote_exec(xdist.remote)
         self.channel.send((self.workerinput, args, option_dict))
         if self.putevent:
-            self.channel.setcallback(
-                self.process_from_remote,
-                endmarker=self.ENDMARK)
+            self.channel.setcallback(self.process_from_remote, endmarker=self.ENDMARK)
 
     def ensure_teardown(self):
-        if hasattr(self, 'channel'):
+        if hasattr(self, "channel"):
             if not self.channel.isclosed():
                 self.log("closing", self.channel)
                 self.channel.close()
             # del self.channel
-        if hasattr(self, 'gateway'):
+        if hasattr(self, "gateway"):
             self.log("exiting", self.gateway)
             self.gateway.exit()
             # del self.gateway
@@ -264,7 +262,7 @@ class WorkerController(object):
         self.sendcommand("runtests", indices=indices)
 
     def send_runtest_all(self):
-        self.sendcommand("runtests_all",)
+        self.sendcommand("runtests_all")
 
     def shutdown(self):
         if not self._down:
@@ -307,33 +305,48 @@ class WorkerController(object):
                 self.notify_inproc(eventname, node=self, **kwargs)
             elif eventname == "workerfinished":
                 self._down = True
-                self.workeroutput = kwargs['workeroutput']
+                self.workeroutput = self.slaveoutput = kwargs["workeroutput"]
                 self.notify_inproc("workerfinished", node=self)
             elif eventname in ("logstart", "logfinish"):
                 self.notify_inproc(eventname, node=self, **kwargs)
-            elif eventname in (
-                    "testreport", "collectreport", "teardownreport"):
+            elif eventname in ("testreport", "collectreport", "teardownreport"):
                 item_index = kwargs.pop("item_index", None)
-                rep = unserialize_report(eventname, kwargs['data'])
+                rep = unserialize_report(eventname, kwargs["data"])
                 if item_index is not None:
                     rep.item_index = item_index
                 self.notify_inproc(eventname, node=self, rep=rep)
             elif eventname == "collectionfinish":
-                self.notify_inproc(eventname, node=self, ids=kwargs['ids'])
+                self.notify_inproc(eventname, node=self, ids=kwargs["ids"])
             elif eventname == "runtest_protocol_complete":
                 self.notify_inproc(eventname, node=self, **kwargs)
             elif eventname == "logwarning":
-                self.notify_inproc(eventname, message=kwargs['message'],
-                                   code=kwargs['code'], nodeid=kwargs['nodeid'],
-                                   fslocation=kwargs['nodeid'])
+                self.notify_inproc(
+                    eventname,
+                    message=kwargs["message"],
+                    code=kwargs["code"],
+                    nodeid=kwargs["nodeid"],
+                    fslocation=kwargs["nodeid"],
+                )
+            elif eventname == "warning_captured":
+                warning_message = unserialize_warning_message(
+                    kwargs["warning_message_data"]
+                )
+                self.notify_inproc(
+                    eventname,
+                    warning_message=warning_message,
+                    when=kwargs["when"],
+                    item=kwargs["item"],
+                )
             else:
                 raise ValueError("unknown event: %s" % (eventname,))
         except KeyboardInterrupt:
             # should not land in receiver-thread
             raise
         except:  # noqa
-            excinfo = py.code.ExceptionInfo()
-            py.builtin.print_("!" * 20, excinfo)
+            from _pytest._code import ExceptionInfo
+
+            excinfo = ExceptionInfo()
+            print("!" * 20, excinfo)
             self.config.notify_exception(excinfo)
             self.shutdown()
             self.notify_inproc("errordown", node=self, error=excinfo)
@@ -348,56 +361,56 @@ def unserialize_report(name, reportdict):
             ReprFileLocation,
             ReprFuncArgs,
             ReprLocals,
-            ReprTraceback
+            ReprTraceback,
         )
-        if reportdict['longrepr']:
-            if 'reprcrash' in reportdict['longrepr'] and 'reprtraceback' in reportdict['longrepr']:
 
-                reprtraceback = reportdict['longrepr']['reprtraceback']
-                reprcrash = reportdict['longrepr']['reprcrash']
+        if reportdict["longrepr"]:
+            if (
+                "reprcrash" in reportdict["longrepr"]
+                and "reprtraceback" in reportdict["longrepr"]
+            ):
+
+                reprtraceback = reportdict["longrepr"]["reprtraceback"]
+                reprcrash = reportdict["longrepr"]["reprcrash"]
 
                 unserialized_entries = []
                 reprentry = None
-                for entry_data in reprtraceback['reprentries']:
-                    data = entry_data['data']
-                    entry_type = entry_data['type']
-                    if entry_type == 'ReprEntry':
+                for entry_data in reprtraceback["reprentries"]:
+                    data = entry_data["data"]
+                    entry_type = entry_data["type"]
+                    if entry_type == "ReprEntry":
                         reprfuncargs = None
                         reprfileloc = None
                         reprlocals = None
-                        if data['reprfuncargs']:
-                            reprfuncargs = ReprFuncArgs(
-                                **data['reprfuncargs'])
-                        if data['reprfileloc']:
-                            reprfileloc = ReprFileLocation(
-                                **data['reprfileloc'])
-                        if data['reprlocals']:
-                            reprlocals = ReprLocals(
-                                data['reprlocals']['lines'])
+                        if data["reprfuncargs"]:
+                            reprfuncargs = ReprFuncArgs(**data["reprfuncargs"])
+                        if data["reprfileloc"]:
+                            reprfileloc = ReprFileLocation(**data["reprfileloc"])
+                        if data["reprlocals"]:
+                            reprlocals = ReprLocals(data["reprlocals"]["lines"])
 
                         reprentry = ReprEntry(
-                            lines=data['lines'],
+                            lines=data["lines"],
                             reprfuncargs=reprfuncargs,
                             reprlocals=reprlocals,
                             filelocrepr=reprfileloc,
-                            style=data['style']
+                            style=data["style"],
                         )
-                    elif entry_type == 'ReprEntryNative':
-                        reprentry = ReprEntryNative(data['lines'])
+                    elif entry_type == "ReprEntryNative":
+                        reprentry = ReprEntryNative(data["lines"])
                     else:
-                        report_unserialization_failure(
-                            entry_type, name, reportdict)
+                        report_unserialization_failure(entry_type, name, reportdict)
                     unserialized_entries.append(reprentry)
-                reprtraceback['reprentries'] = unserialized_entries
+                reprtraceback["reprentries"] = unserialized_entries
 
                 exception_info = ReprExceptionInfo(
                     reprtraceback=ReprTraceback(**reprtraceback),
                     reprcrash=ReprFileLocation(**reprcrash),
                 )
 
-                for section in reportdict['longrepr']['sections']:
+                for section in reportdict["longrepr"]["sections"]:
                     exception_info.addsection(*section)
-                reportdict['longrepr'] = exception_info
+                reportdict["longrepr"] = exception_info
         return reportdict
 
     if name == "testreport":
@@ -406,15 +419,42 @@ def unserialize_report(name, reportdict):
         return runner.CollectReport(**assembled_report(reportdict))
 
 
+def unserialize_warning_message(data):
+    import warnings
+    import importlib
+
+    if data["message_module"]:
+        mod = importlib.import_module(data["message_module"])
+        cls = getattr(mod, data["message_class_name"])
+        message = cls(*data["message_args"])
+    else:
+        message = data["message_str"]
+
+    if data["category_module"]:
+        mod = importlib.import_module(data["category_module"])
+        category = getattr(mod, data["category_class_name"])
+    else:
+        category = None
+
+    kwargs = {"message": message, "category": category}
+    # access private _WARNING_DETAILS because the attributes vary between Python versions
+    for attr_name in warnings.WarningMessage._WARNING_DETAILS:
+        if attr_name in ("message", "category"):
+            continue
+        kwargs[attr_name] = data[attr_name]
+
+    return warnings.WarningMessage(**kwargs)
+
+
 def report_unserialization_failure(type_name, report_name, reportdict):
     from pprint import pprint
-    url = 'https://github.com/pytest-dev/pytest-xdist/issues'
+
+    url = "https://github.com/pytest-dev/pytest-xdist/issues"
     stream = py.io.TextIO()
-    pprint('-' * 100, stream=stream)
-    pprint('INTERNALERROR: Unknown entry type returned: %s' % type_name,
-           stream=stream)
-    pprint('report_name: %s' % report_name, stream=stream)
+    pprint("-" * 100, stream=stream)
+    pprint("INTERNALERROR: Unknown entry type returned: %s" % type_name, stream=stream)
+    pprint("report_name: %s" % report_name, stream=stream)
     pprint(reportdict, stream=stream)
-    pprint('Please report this bug at %s' % url, stream=stream)
-    pprint('-' * 100, stream=stream)
+    pprint("Please report this bug at %s" % url, stream=stream)
+    pprint("-" * 100, stream=stream)
     assert 0, stream.getvalue()