Release 2.1.0

This makes using psutil optional and opens up the possibility of customization
through the pytest_xdist_auto_num_workers hook, making things like #477 possible.

Fix #585

.appveyor.yml

@@ -1,13 +1,11 @@
 environment:
   matrix:
-  - TOXENV: "py27-pytestlatest"
-  - TOXENV: "py34-pytestlatest"
   - TOXENV: "py35-pytestlatest"
   - TOXENV: "py36-pytestlatest"
   - TOXENV: "py37-pytestlatest"
   - TOXENV: "py38-pytestlatest"
   - TOXENV: "py38-pytestmaster"
-  - TOXENV: "py38-pytestfeatures"
+  - TOXENV: "py38-psutil"
 
 install:
   - C:\Python38\python -m pip install -U pip setuptools virtualenv

.pre-commit-config.yaml

@@ -1,18 +1,23 @@
 repos:
 -   repo: https://github.com/ambv/black
-    rev: 18.6b4
+    rev: 19.10b0
     hooks:
     -   id: black
-        args: [--safe, --quiet]
+        args: [--safe, --quiet, --target-version, py35]
         language_version: python3.7
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v1.3.0
+    rev: v2.4.0
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer
     -   id: check-yaml
     -   id: debug-statements
     -   id: flake8
+-   repo: https://github.com/asottile/pyupgrade
+    rev: v2.7.2
+    hooks:
+    -   id: pyupgrade
+        args: [--py3-plus]
 -   repo: local
     hooks:
     -   id: rst

.travis.yml

@@ -32,22 +32,20 @@ jobs:
           - $HOME/.cache/pre-commit
     - python: '3.8'
       env: TOXENV=py38-pytestlatest
-    - python: '2.7'
-      env: TOXENV=py27-pytestlatest
 
     - stage: test
-      python: "3.4"
+      python: "3.5"
-      env: TOXENV=py34-pytestlatest
-    - python: "3.5"
       env: TOXENV=py35-pytestlatest
     - python: "3.6"
       env: TOXENV=py36-pytestlatest
     - python: "3.7"
       env: TOXENV=py37-pytestlatest
+    - python: "3.9-dev"
+      env: TOXENV=py39-pytestlatest
     - python: "3.8"
       env: TOXENV=py38-pytestmaster
     - python: "3.8"
-      env: TOXENV=py38-pytestfeatures
+      env: TOXENV=py38-psutil
 
     - stage: deploy
       python: '3.8'

CHANGELOG.rst

@@ -1,3 +1,101 @@
+pytest-xdist 2.1.0 (2020-08-25)
+===============================
+
+Features
+--------
+
+- `#585 <https://github.com/pytest-dev/pytest-xdist/issues/585>`_: New ``pytest_xdist_auto_num_workers`` hook can be implemented by plugins or ``conftest.py`` files to control the number of workers when ``--numprocesses=auto`` is given in the command-line.
+
+
+Trivial Changes
+---------------
+
+- `#585 <https://github.com/pytest-dev/pytest-xdist/issues/585>`_: ``psutil`` has proven to make ``pytest-xdist`` installation in certain platforms and containers problematic, so to use it for automatic number of CPUs detection users need to install the ``psutil`` extra::
+
+      pip install pytest-xdist[psutil]
+
+
+pytest-xdist 2.0.0 (2020-08-12)
+===============================
+
+Deprecations and Removals
+-------------------------
+
+- `#541 <https://github.com/pytest-dev/pytest-xdist/issues/541>`_: Drop backward-compatibility "slave" aliases related to worker nodes.  We deliberately moved away from this terminology years ago, and it seems like the right time to finish the deprecation and removal process.
+
+- `#569 <https://github.com/pytest-dev/pytest-xdist/issues/569>`_: ``pytest-xdist`` no longer supports Python 2.7.
+
+
+Features
+--------
+
+- `#504 <https://github.com/pytest-dev/pytest-xdist/issues/504>`_: New functions ``xdist.is_xdist_worker``, ``xdist.is_xdist_master``, ``xdist.get_xdist_worker_id``, to easily identify the current node.
+
+
+Bug Fixes
+---------
+
+- `#471 <https://github.com/pytest-dev/pytest-xdist/issues/471>`_: Fix issue with Rsync reporting in quiet mode.
+
+- `#553 <https://github.com/pytest-dev/pytest-xdist/issues/553>`_: When using ``-n auto``, count the number of physical CPU cores instead of logical ones.
+
+
+Trivial Changes
+---------------
+
+- `#541 <https://github.com/pytest-dev/pytest-xdist/issues/541>`_: ``pytest-xdist`` now requires ``pytest>=6.0``.
+
+
+pytest-xdist 1.34.0 (2020-07-27)
+================================
+
+Features
+--------
+
+- `#549 <https://github.com/pytest-dev/pytest-xdist/issues/549>`_: Make ``--pdb`` imply ``--dist no``, as the two options cannot really work together at the moment.
+
+
+Bug Fixes
+---------
+
+- `#478 <https://github.com/pytest-dev/pytest-xdist/issues/478>`_: Fix regression with duplicated arguments via $PYTEST_ADDOPTS in 1.30.0.
+
+- `#558 <https://github.com/pytest-dev/pytest-xdist/issues/558>`_: Fix ``rsyncdirs`` usage with pytest 6.0.
+
+- `#562 <https://github.com/pytest-dev/pytest-xdist/issues/562>`_: Do not trigger the deprecated ``pytest_warning_captured`` in pytest 6.0+.
+
+
+pytest-xdist 1.33.0 (2020-07-09)
+================================
+
+Features
+--------
+
+- `#554 <https://github.com/pytest-dev/pytest-xdist/issues/554>`_: Fix warnings support for upcoming pytest 6.0.
+
+
+Trivial Changes
+---------------
+
+- `#548 <https://github.com/pytest-dev/pytest-xdist/issues/548>`_: SCM and CI files are no longer included in the source distribution.
+
+
+pytest-xdist 1.32.0 (2020-05-03)
+================================
+
+Deprecations and Removals
+-------------------------
+
+- `#475 <https://github.com/pytest-dev/pytest-xdist/issues/475>`_: Drop support for EOL Python 3.4.
+
+
+Features
+--------
+
+- `#524 <https://github.com/pytest-dev/pytest-xdist/issues/524>`_: Add `testrun_uid` fixture. This is a shared value that uniquely identifies a test run among all workers.
+  This also adds a `PYTEST_XDIST_TESTRUNUID` environment variable that is accessible within a test as well as a command line option `--testrunuid` to manually set the value from outside.
+
+
 pytest-xdist 1.31.0 (2019-12-19)
 ================================
 

ISSUES.txt

@@ -1,31 +0,0 @@
-next release critical
------------------------------------------------
-tag: bug
-
-miserably fails: --dist=each --tx popen --tx socket=...
-
-
-rename / hooks
------------------------------------------------
-tag: bug
-
-node -> slave
-transition for hooks?
-configure_node -> configure_slave
-
-allow to remotely run xdist tests with xdist
------------------------------------------------
-tag: feature
-
-allow to run xdist own tests using its own mechanism.
-currently this doesn't work because the remote side
-has no pytest plugin.   How to configure/do
-register "xdist.plugin" on the remote side?
-
-see to avoid any "from _pytest" internal imports
------------------------------------------------
-tag: feature
-
-currently tests and even xdist core code imports
-names from the internal _pytest namespace.
-See to avoid it.

MANIFEST.in

@@ -0,0 +1,5 @@
+exclude .appveyor.yml
+exclude .gitignore
+exclude .pre-commit-config.yaml
+exclude .travis.yml
+prune .github

README.rst

@@ -57,43 +57,46 @@ Install the plugin with::
 
     pip install pytest-xdist
 
-or use the package in develop/in-place mode with
-a checkout of the `pytest-xdist repository`_ ::
 
-    pip install --editable .
+To use ``psutil`` for detection of the number of CPUs available, install the ``psutil`` extra::
+
+    pip install pytest-xdist[psutil]
+
 
 .. _parallelization:
 
 Speed up test runs by sending tests to multiple CPUs
 ----------------------------------------------------
 
-To send tests to multiple CPUs, type::
+To send tests to multiple CPUs, use the ``-n`` (or ``--numprocesses``) option::
 
-    pytest -n NUM
+    pytest -n NUMCPUS
 
-Especially for longer running tests or tests requiring
+Pass ``-n auto`` to use as many processes as your computer has CPU cores. This
-a lot of I/O this can lead to considerable speed ups. This option can
+can lead to considerable speed ups, especially if your test suite takes a
-also be set to ``auto`` for automatic detection of the number of CPUs.
+noticeable amount of time.
 
-If a test crashes the interpreter, pytest-xdist will automatically restart
+If a test crashes a worker, pytest-xdist will automatically restart that worker
-that worker and report the failure as usual. You can use the
+and report the test’s failure. You can use the ``--max-worker-restart`` option
-``--max-worker-restart`` option to limit the number of workers that can
+to limit the number of worker restarts that are allowed, or disable restarting
-be restarted, or disable restarting altogether using ``--max-worker-restart=0``.
+altogether using ``--max-worker-restart 0``.
 
-By default, the ``-n`` option will send pending tests to any worker that is available, without
+By default, using ``--numprocesses`` will send pending tests to any worker that
-any guaranteed order, but you can control this with these options:
+is available, without any guaranteed order. You can change the test
+distribution algorithm this with the ``--dist`` option. It takes these values:
 
-* ``--dist=loadscope``: tests will be grouped by **module** for *test functions* and
+* ``--dist no``: The default algorithm, distributing one test at a time.
-  by **class** for *test methods*, then each group will be sent to an available worker,
-  guaranteeing that all tests in a group run in the same process. This can be useful if you have
-  expensive module-level or class-level fixtures. Currently the groupings can't be customized,
-  with grouping by class takes priority over grouping by module.
-  This feature was added in version ``1.19``.
 
-* ``--dist=loadfile``: tests will be grouped by file name, and then will be sent to an available
+* ``--dist loadscope``: Tests are grouped by **module** for *test functions*
-  worker, guaranteeing that all tests in a group run in the same worker. This feature was added
+  and by **class** for *test methods*. Groups are distributed to available
-  in version ``1.21``.
+  workers as whole units. This guarantees that all tests in a group run in the
+  same process. This can be useful if you have expensive module-level or
+  class-level fixtures. Grouping by class takes priority over grouping by
+  module.
 
+* ``--dist loadfile``: Tests are grouped by their containing file. Groups are
+  distributed to available workers as whole units. This guarantees that all
+  tests in a file run in the same worker.
 
 Making session-scoped fixtures execute only once
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -124,7 +127,7 @@ Here is the code:
 
     @pytest.fixture(scope="session")
     def session_data(tmp_path_factory, worker_id):
-        if not worker_id:
+        if worker_id == "master":
             # not executing in with multiple workers, just produce the data and let
             # pytest's fixture caching do its job
             return produce_expensive_data()
@@ -266,7 +269,7 @@ a test or fixture, you may use the ``worker_id`` fixture to do so:
 When ``xdist`` is disabled (running with ``-n0`` for example), then
 ``worker_id`` will return ``"master"``.
 
-Additionally, worker processes have the following environment variables
+Worker processes also have the following environment variables
 defined:
 
 * ``PYTEST_XDIST_WORKER``: the name of the worker, e.g., ``"gw2"``.
@@ -276,8 +279,71 @@ defined:
 The information about the worker_id in a test is stored in the ``TestReport`` as
 well, under the ``worker_id`` attribute.
 
-Acessing ``sys.argv`` from the master node in workers
+Since version 2.0, the following functions are also available in the ``xdist`` module:
------------------------------------------------------
+
+.. code-block:: python
+
+    def is_xdist_worker(request_or_session) -> bool:
+        """Return `True` if this is an xdist worker, `False` otherwise
+
+        :param request_or_session: the `pytest` `request` or `session` object
+        """
+
+    def is_xdist_master(request_or_session) -> bool:
+        """Return `True` if this is the xdist master, `False` otherwise
+
+        Note: this method also returns `False` when distribution has not been
+        activated at all.
+
+        :param request_or_session: the `pytest` `request` or `session` object
+        """
+
+    def get_xdist_worker_id(request_or_session) -> str:
+        """Return the id of the current worker ('gw0', 'gw1', etc) or 'master'
+        if running on the 'master' node.
+
+        If not distributing tests (for example passing `-n0` or not passing `-n` at all) also return 'master'.
+
+        :param request_or_session: the `pytest` `request` or `session` object
+        """
+
+
+Uniquely identifying the current test run
+-----------------------------------------
+
+*New in version 1.32.*
+
+If you need to globally distinguish one test run from others in your
+workers, you can use the ``testrun_uid`` fixture. For instance, let's say you
+wanted to create a separate database for each test run:
+
+.. code-block:: python
+
+    import pytest
+    from posix_ipc import Semaphore, O_CREAT
+
+    @pytest.fixture(scope="session", autouse=True)
+    def create_unique_database(testrun_uid):
+        """ create a unique database for this particular test run """
+        database_url = f"psql://myapp-{testrun_uid}"
+
+        with Semaphore(f"/{testrun_uid}-lock", flags=O_CREAT, initial_value=1):
+            if not database_exists(database_url):
+                create_database(database_url)
+
+    @pytest.fixture()
+    def db(testrun_uid):
+        """ retrieve unique database """
+        database_url = f"psql://myapp-{testrun_uid}"
+        return database_get_instance(database_url)
+
+
+Additionally, during a test run, the following environment variable is defined:
+
+* ``PYTEST_XDIST_TESTRUNUID``: the unique id of the test run.
+
+Accessing ``sys.argv`` from the master node in workers
+------------------------------------------------------
 
 To access the ``sys.argv`` passed to the command-line of the master node, use
 ``request.config.workerinput["mainargv"]``.

setup.cfg

@@ -1,6 +1,3 @@
-[bdist_wheel]
-universal = 1
-
 [metadata]
 license_file = LICENSE
 

setup.py

@@ -1,6 +1,6 @@
 from setuptools import setup, find_packages
 
-install_requires = ["execnet>=1.1", "pytest>=4.4.0", "pytest-forked", "six"]
+install_requires = ["execnet>=1.1", "pytest>=6.0.0", "pytest-forked"]
 
 
 with open("README.rst") as f:
@@ -9,8 +9,7 @@ with open("README.rst") as f:
 setup(
     name="pytest-xdist",
     use_scm_version={"write_to": "src/xdist/_version.py"},
-    description="pytest xdist plugin for distributed testing"
+    description="pytest xdist plugin for distributed testing and loop-on-failing modes",
-    " and loop-on-failing modes",
     long_description=long_description,
     license="MIT",
     author="holger krekel and contributors",
@@ -19,12 +18,12 @@ setup(
     platforms=["linux", "osx", "win32"],
     packages=find_packages(where="src"),
     package_dir={"": "src"},
-    extras_require={"testing": ["filelock"]},
+    extras_require={"testing": ["filelock"], "psutil": ["psutil>=3.0"]},
     entry_points={
         "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=">=3.5",
     install_requires=install_requires,
     setup_requires=["setuptools_scm"],
     classifiers=[
@@ -39,10 +38,8 @@ setup(
         "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 :: Only",
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",

src/xdist/__init__.py

@@ -1,3 +1,4 @@
+from xdist.plugin import is_xdist_worker, is_xdist_master, get_xdist_worker_id
 from xdist._version import version as __version__
 
-__all__ = ["__version__"]
+__all__ = ["__version__", "is_xdist_worker", "is_xdist_master", "get_xdist_worker_id"]

src/xdist/dsession.py

@@ -10,14 +10,14 @@ from xdist.scheduler import (
 )
 
 
-from six.moves.queue import Empty, Queue
+from queue import Empty, Queue
 
 
 class Interrupted(KeyboardInterrupt):
     """ signals an immediate interruption. """
 
 
-class DSession(object):
+class DSession:
     """A pytest plugin which runs a distributed test session
 
     At the beginning of the test session this creates a NodeManager
@@ -150,9 +150,6 @@ class DSession(object):
         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
-
         self.config.hook.pytest_testnodeready(node=node)
         if self.shuttingdown:
             node.shutdown()
@@ -169,7 +166,7 @@ class DSession(object):
         """
         self.config.hook.pytest_testnodedown(node=node, error=None)
         if node.workeroutput["exitstatus"] == 2:  # keyboard-interrupt
-            self.shouldstop = "%s received keyboard-interrupt" % (node,)
+            self.shouldstop = "{} received keyboard-interrupt".format(node)
             self.worker_errordown(node, "keyboard-interrupt")
             return
         if node in self.sched.nodes:
@@ -271,16 +268,18 @@ class DSession(object):
         assert not rep.passed
         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."""
+        """Emitted when a node calls the pytest_warning_captured hook (deprecated in 6.0)."""
         kwargs = dict(warning_message=warning_message, when=when, item=item)
         self.config.hook.pytest_warning_captured.call_historic(kwargs=kwargs)
 
+    def worker_warning_recorded(self, warning_message, when, nodeid, location):
+        """Emitted when a node calls the pytest_warning_recorded hook."""
+        kwargs = dict(
+            warning_message=warning_message, when=when, nodeid=nodeid, location=location
+        )
+        self.config.hook.pytest_warning_recorded.call_historic(kwargs=kwargs)
+
     def _clone_node(self, node):
         """Return new node based on an existing one.
 
@@ -321,7 +320,7 @@ class DSession(object):
         # XXX count no of failures and retry N times
         runner = self.config.pluginmanager.getplugin("runner")
         fspath = nodeid.split("::")[0]
-        msg = "worker %r crashed while running %r" % (worker.gateway.id, nodeid)
+        msg = "worker {!r} crashed while running {!r}".format(worker.gateway.id, nodeid)
         rep = runner.TestReport(
             nodeid, (fspath, None, fspath), (), "failed", msg, "???"
         )
@@ -329,7 +328,7 @@ class DSession(object):
         self.config.hook.pytest_runtest_logreport(report=rep)
 
 
-class TerminalDistReporter(object):
+class TerminalDistReporter:
     def __init__(self, config):
         self.config = config
         self.tr = config.pluginmanager.getplugin("terminalreporter")
@@ -351,7 +350,9 @@ class TerminalDistReporter(object):
 
     def getstatus(self):
         if self.config.option.verbose >= 0:
-            parts = ["%s %s" % (spec.id, self._status[spec.id]) for spec in self._specs]
+            parts = [
+                "{} {}".format(spec.id, self._status[spec.id]) for spec in self._specs
+            ]
             return " / ".join(parts)
         else:
             return "bringing up nodes..."
@@ -386,14 +387,16 @@ class TerminalDistReporter(object):
     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 = "[{}] Python {}".format(
+                d["id"], d["version"].replace("\n", " -- ")
+            )
             self.rewrite(infoline, newline=True)
         self.setstatus(node.gateway.spec, "ok")
 
     def pytest_testnodedown(self, node, error):
         if not error:
             return
-        self.write_line("[%s] node down: %s" % (node.gateway.id, error))
+        self.write_line("[{}] node down: {}".format(node.gateway.id, error))
 
 
 def get_default_max_worker_restart(config):

src/xdist/looponfail.py

@@ -6,7 +6,6 @@
     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
@@ -55,7 +54,7 @@ def looponfail_main(config):
         print()
 
 
-class RemoteControl(object):
+class RemoteControl:
     def __init__(self, config):
         self.config = config
         self.failures = []
@@ -136,7 +135,7 @@ def repr_pytest_looponfailinfo(failreports, rootdirs):
                 tr.line(report, red=True)
     tr.sep("#", "waiting for changes", bold=True)
     for rootdir in rootdirs:
-        tr.line("### Watching:   %s" % (rootdir,), bold=True)
+        tr.line("### Watching:   {}".format(rootdir), bold=True)
 
 
 def init_worker_session(channel, args, option_dict):
@@ -165,7 +164,7 @@ def init_worker_session(channel, args, option_dict):
     WorkerFailSession(config, channel).main()
 
 
-class WorkerFailSession(object):
+class WorkerFailSession:
     def __init__(self, config, channel):
         self.config = config
         self.channel = channel
@@ -220,7 +219,7 @@ class WorkerFailSession(object):
         self.channel.send((trails, failreports, self.collection_failed))
 
 
-class StatRecorder(object):
+class StatRecorder:
     def __init__(self, rootdirlist):
         self.rootdirlist = rootdirlist
         self.statcache = {}

src/xdist/newhooks.py

@@ -55,3 +55,13 @@ def pytest_xdist_node_collection_finished(node, ids):
 @pytest.mark.firstresult
 def pytest_xdist_make_scheduler(config, log):
     """ return a node scheduler implementation """
+
+
+@pytest.mark.firstresult
+def pytest_xdist_auto_num_workers(config):
+    """
+    Return the number of workers to spawn when ``--numprocesses=auto`` is given in the
+    command-line.
+
+    .. versionadded:: 2.1
+    """

src/xdist/plugin.py

@@ -1,12 +1,25 @@
 import os
+import uuid
 
 import py
 import pytest
 
 
-def auto_detect_cpus():
+def pytest_xdist_auto_num_workers():
+    try:
+        import psutil
+    except ImportError:
+        pass
+    else:
+        count = psutil.cpu_count(logical=False) or psutil.cpu_count()
+        if count:
+            return count
     try:
         from os import sched_getaffinity
+
+        def cpu_count():
+            return len(sched_getaffinity(0))
+
     except ImportError:
         if os.environ.get("TRAVIS") == "true":
             # workaround https://bitbucket.org/pypy/pypy/issues/2375
@@ -15,11 +28,6 @@ def auto_detect_cpus():
             from os import cpu_count
         except ImportError:
             from multiprocessing import cpu_count
-    else:
-
-        def cpu_count():
-            return len(sched_getaffinity(0))
-
     try:
         n = cpu_count()
     except NotImplementedError:
@@ -27,13 +35,9 @@ def auto_detect_cpus():
     return n if n else 1
 
 
-class AutoInt(int):
-    """Mark value as auto-detected."""
-
-
 def parse_numprocesses(s):
     if s == "auto":
-        return AutoInt(auto_detect_cpus())
+        return "auto"
     elif s is not None:
         return int(s)
 
@@ -61,14 +65,11 @@ def pytest_addoption(parser):
     )
     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"
+        "when crashed (set to zero to disable this feature)",
-        "'--max-slave-restart' option is deprecated and will be removed in "
-        "a future release",
     )
     group.addoption(
         "--dist",
@@ -122,12 +123,22 @@ def pytest_addoption(parser):
         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",
     )
+    group.addoption(
+        "--testrunuid",
+        action="store",
+        help=(
+            "provide an identifier shared amongst all workers as the value of "
+            "the 'testrun_uid' fixture,\n\n,"
+            "if not provided, 'testrun_uid' is filled with a new unique string "
+            "on every test run."
+        ),
+    )
+
     parser.addini(
         "rsyncdirs",
         "list of (relative) paths to be rsynced for remote distributed testing.",
@@ -179,8 +190,13 @@ def pytest_configure(config):
 @pytest.mark.tryfirst
 def pytest_cmdline_main(config):
     usepdb = config.getoption("usepdb", False)  # a core option
-    if isinstance(config.option.numprocesses, AutoInt):
+    if config.option.numprocesses == "auto":
-        config.option.numprocesses = 0 if usepdb else int(config.option.numprocesses)
+        if usepdb:
+            config.option.numprocesses = 0
+            config.option.dist = "no"
+        else:
+            auto_num_cpus = config.hook.pytest_xdist_auto_num_workers(config=config)
+            config.option.numprocesses = auto_num_cpus
 
     if config.option.numprocesses:
         if config.option.dist == "no":
@@ -192,25 +208,66 @@ def pytest_cmdline_main(config):
     if config.option.distload:
         config.option.dist = "load"
     val = config.getvalue
-    if not val("collectonly"):
+    if not val("collectonly") and val("dist") != "no" and usepdb:
-        if val("dist") != "no":
+        raise pytest.UsageError(
-            if usepdb:
+            "--pdb is incompatible with distributing tests; try using -n0 or -nauto."
-                raise pytest.UsageError(
+        )  # noqa: E501
-                    "--pdb is incompatible with distributing tests; try using -n0 or -nauto."
-                )  # noqa: E501
 
 
 # -------------------------------------------------------------------------
-# fixtures
+# fixtures and API to easily know the role of current node
 # -------------------------------------------------------------------------
 
 
+def is_xdist_worker(request_or_session) -> bool:
+    """Return `True` if this is an xdist worker, `False` otherwise
+
+    :param request_or_session: the `pytest` `request` or `session` object
+    """
+    return hasattr(request_or_session.config, "workerinput")
+
+
+def is_xdist_master(request_or_session) -> bool:
+    """Return `True` if this is the xdist master, `False` otherwise
+
+    Note: this method also returns `False` when distribution has not been
+    activated at all.
+
+    :param request_or_session: the `pytest` `request` or `session` object
+    """
+    return (
+        not is_xdist_worker(request_or_session)
+        and request_or_session.config.option.dist != "no"
+    )
+
+
+def get_xdist_worker_id(request_or_session) -> str:
+    """Return the id of the current worker ('gw0', 'gw1', etc) or 'master'
+    if running on the 'master' node.
+
+    If not distributing tests (for example passing `-n0` or not passing `-n` at all)
+    also return 'master'.
+
+    :param request_or_session: the `pytest` `request` or `session` object
+    """
+    if hasattr(request_or_session.config, "workerinput"):
+        return request_or_session.config.workerinput["workerid"]
+    else:
+        return "master"
+
+
 @pytest.fixture(scope="session")
 def worker_id(request):
     """Return the id of the current worker ('gw0', 'gw1', etc) or 'master'
     if running on the master node.
     """
+    return get_xdist_worker_id(request)
+
+
+@pytest.fixture(scope="session")
+def testrun_uid(request):
+    """Return the unique id of the current test."""
     if hasattr(request.config, "workerinput"):
-        return request.config.workerinput["workerid"]
+        return request.config.workerinput["testrunuid"]
     else:
-        return "master"
+        return uuid.uuid4().hex

src/xdist/remote.py

@@ -11,17 +11,17 @@ import os
 import time
 
 import py
-import _pytest.hookspec
 import pytest
 from execnet.gateway_base import dumps, DumpError
 
 from _pytest.config import _prepareconfig, Config
 
 
-class WorkerInteractor(object):
+class WorkerInteractor:
     def __init__(self, config, channel):
         self.config = config
         self.workerid = config.workerinput.get("workerid", "?")
+        self.testrunuid = config.workerinput["testrunuid"]
         self.log = py.log.Producer("worker-%s" % self.workerid)
         if not config.option.debug:
             py.log.setconsumer(self.log._keywords, None)
@@ -100,11 +100,8 @@ class WorkerInteractor(object):
     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
+    def pytest_runtest_logfinish(self, nodeid, location):
-    if hasattr(_pytest.hookspec, "pytest_runtest_logfinish"):
+        self.sendevent("logfinish", nodeid=nodeid, location=location)
-
-        def pytest_runtest_logfinish(self, nodeid, location):
-            self.sendevent("logfinish", nodeid=nodeid, location=location)
 
     def pytest_runtest_logreport(self, report):
         data = self.config.hook.pytest_report_to_serializable(
@@ -112,6 +109,7 @@ class WorkerInteractor(object):
         )
         data["item_index"] = self.item_index
         data["worker_id"] = self.workerid
+        data["testrun_uid"] = self.testrunuid
         assert self.session.items[self.item_index].nodeid == report.nodeid
         self.sendevent("testreport", data=data)
 
@@ -123,31 +121,14 @@ class WorkerInteractor(object):
             )
             self.sendevent("collectreport", data=data)
 
-    # the pytest_logwarning hook was deprecated since pytest 4.0
+    def pytest_warning_recorded(self, warning_message, when, nodeid, location):
-    if hasattr(
+        self.sendevent(
-        _pytest.hookspec, "pytest_logwarning"
+            "warning_recorded",
-    ) and not _pytest.hookspec.pytest_logwarning.pytest_spec.get("warn_on_impl"):
+            warning_message_data=serialize_warning_message(warning_message),
-
+            when=when,
-        def pytest_logwarning(self, message, code, nodeid, fslocation):
+            nodeid=nodeid,
-            self.sendevent(
+            location=location,
-                "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_warning_message(warning_message):
@@ -238,6 +219,7 @@ if __name__ == "__channelexec__":
             importpath + os.pathsep + os.environ.get("PYTHONPATH", "")
         )
 
+    os.environ["PYTEST_XDIST_TESTRUNUID"] = workerinput["testrunuid"]
     os.environ["PYTEST_XDIST_WORKER"] = workerinput["workerid"]
     os.environ["PYTEST_XDIST_WORKER_COUNT"] = str(workerinput["workercount"])
 
@@ -251,8 +233,5 @@ if __name__ == "__channelexec__":
     config._parser.prog = os.path.basename(workerinput["mainargv"][0])
     config.workerinput = workerinput
     config.workeroutput = {}
-    # TODO: deprecated name, backward compatibility only. Remove it in future
-    config.slaveinput = config.workerinput
-    config.slaveoutput = config.workeroutput
     interactor = WorkerInteractor(config, channel)
     config.hook.pytest_cmdline_main(config=config)

src/xdist/report.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 from difflib import unified_diff
 
 
@@ -13,9 +12,9 @@ def report_collection_diff(from_collection, to_collection, from_id, to_id):
 
     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}. "
+        "Different tests were collected between {from_id} and {to_id}. "
-        u"The difference is:\n"
+        "The difference is:\n"
-        u"{diff}"
+        "{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

src/xdist/scheduler/each.py

@@ -4,7 +4,7 @@ from xdist.workermanage import parse_spec_config
 from xdist.report import report_collection_diff
 
 
-class EachScheduling(object):
+class EachScheduling:
     """Implement scheduling of test items on all nodes
 
     If a node gets added after the test run is started then it is

src/xdist/scheduler/load.py

@@ -7,7 +7,7 @@ from xdist.workermanage import parse_spec_config
 from xdist.report import report_collection_diff
 
 
-class LoadScheduling(object):
+class LoadScheduling:
     """Implement load scheduling across nodes.
 
     This distributes the tests collected across all nodes so each test

src/xdist/scheduler/loadfile.py

@@ -21,7 +21,7 @@ class LoadFileScheduling(LoadScopeScheduling):
     """
 
     def __init__(self, config, log=None):
-        super(LoadFileScheduling, self).__init__(config, log)
+        super().__init__(config, log)
         if log is None:
             self.log = Producer("loadfilesched")
         else:

src/xdist/scheduler/loadscope.py

@@ -6,7 +6,7 @@ from xdist.report import report_collection_diff
 from xdist.workermanage import parse_spec_config
 
 
-class LoadScopeScheduling(object):
+class LoadScopeScheduling:
     """Implement load scheduling across nodes, but grouping test by scope.
 
     This distributes the tests collected across all nodes so each test is run
@@ -358,12 +358,12 @@ class LoadScopeScheduling(object):
         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 {} 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 {}".format(unused_node))
                 unused_node.shutdown()
 
         # Assign initial workload

src/xdist/workermanage.py

@@ -1,8 +1,8 @@
-from __future__ import print_function
 import fnmatch
 import os
 import re
 import sys
+import uuid
 
 import py
 import pytest
@@ -28,13 +28,16 @@ def parse_spec_config(config):
     return xspeclist
 
 
-class NodeManager(object):
+class NodeManager:
     EXIT_TIMEOUT = 10
     DEFAULT_IGNORES = [".*", "*.pyc", "*.pyo", "*~"]
 
     def __init__(self, config, specs=None, defaultchdir="pyexecnetcache"):
         self.config = config
         self.trace = self.config.trace.get("nodemanager")
+        self.testrunuid = self.config.getoption("testrunuid")
+        if self.testrunuid is None:
+            self.testrunuid = uuid.uuid4().hex
         self.group = execnet.Group()
         if specs is None:
             specs = self._getxspecs()
@@ -59,10 +62,7 @@ class NodeManager(object):
     def setup_nodes(self, putevent):
         self.config.hook.pytest_xdist_setupnodes(config=self.config, specs=self.specs)
         self.trace("setting up nodes")
-        nodes = []
+        return [self.setup_node(spec, putevent) for spec in self.specs]
-        for spec in self.specs:
-            nodes.append(self.setup_node(spec, putevent))
-        return nodes
 
     def setup_node(self, spec, putevent):
         gw = self.group.makegateway(spec)
@@ -89,8 +89,16 @@ class NodeManager(object):
         import pytest
         import _pytest
 
-        pytestpath = pytest.__file__.rstrip("co")
+        def get_dir(p):
-        pytestdir = py.path.local(_pytest.__file__).dirpath()
+            """Return the directory path if p is a package or the path to the .py file otherwise."""
+            stripped = p.rstrip("co")
+            if os.path.basename(stripped) == "__init__.py":
+                return os.path.dirname(p)
+            else:
+                return stripped
+
+        pytestpath = get_dir(pytest.__file__)
+        pytestdir = get_dir(_pytest.__file__)
         config = self.config
         candidates = [py._pydir, pytestpath, pytestdir]
         candidates += config.option.rsyncdir
@@ -101,7 +109,7 @@ class NodeManager(object):
         for root in candidates:
             root = py.path.local(root).realpath()
             if not root.check():
-                raise pytest.UsageError("rsyncdir doesn't exist: %r" % (root,))
+                raise pytest.UsageError("rsyncdir doesn't exist: {!r}".format(root))
             if root not in roots:
                 roots.append(root)
         return roots
@@ -114,7 +122,7 @@ class NodeManager(object):
 
         return {
             "ignores": ignores,
-            "verbose": getattr(self.config.option, "verbose", False),
+            "verbose": getattr(self.config.option, "verbose", 0),
         }
 
     def rsync(self, gateway, source, notify=None, verbose=False, ignores=None):
@@ -154,12 +162,11 @@ class HostRSync(execnet.RSync):
 
     def __init__(self, sourcedir, *args, **kwargs):
         self._synced = {}
-        self._ignores = []
         ignores = kwargs.pop("ignores", None) or []
-        for x in ignores:
+        self._ignores = [
-            x = getattr(x, "strpath", x)
+            re.compile(fnmatch.translate(getattr(x, "strpath", x))) for x in ignores
-            self._ignores.append(re.compile(fnmatch.translate(x)))
+        ]
-        super(HostRSync, self).__init__(sourcedir=sourcedir, **kwargs)
+        super().__init__(sourcedir=sourcedir, **kwargs)
 
     def filter(self, path):
         path = py.path.local(path)
@@ -171,15 +178,13 @@ class HostRSync(execnet.RSync):
 
     def add_target_host(self, gateway, finished=None):
         remotepath = os.path.basename(self._sourcedir)
-        super(HostRSync, self).add_target(
+        super().add_target(gateway, remotepath, finishedcallback=finished, delete=True)
-            gateway, remotepath, finishedcallback=finished, delete=True
-        )
 
     def _report_send_file(self, gateway, modified_rel_path):
-        if self._verbose:
+        if self._verbose > 0:
             path = os.path.basename(self._sourcedir) + "/" + modified_rel_path
             remotepath = gateway.spec.chdir
-            print("%s:%s <= %s" % (gateway.spec, remotepath, path))
+            print("{}:{} <= {}".format(gateway.spec, remotepath, path))
 
 
 def make_reltoroot(roots, args):
@@ -198,12 +203,12 @@ def make_reltoroot(roots, args):
                 parts[0] = root.basename + "/" + x
                 break
         else:
-            raise ValueError("arg %s not relative to an rsync root" % (arg,))
+            raise ValueError("arg {} not relative to an rsync root".format(arg))
         result.append(splitcode.join(parts))
     return result
 
 
-class WorkerController(object):
+class WorkerController:
     ENDMARK = -1
 
     class RemoteHook:
@@ -220,12 +225,9 @@ class WorkerController(object):
         self.workerinput = {
             "workerid": gateway.id,
             "workercount": len(nodemanager.specs),
-            "slaveid": gateway.id,
+            "testrunuid": nodemanager.testrunuid,
-            "slavecount": len(nodemanager.specs),
             "mainargv": sys.argv,
         }
-        # TODO: deprecated name, backward compatibility only. Remove it in future
-        self.slaveinput = self.workerinput
         self._down = False
         self._shutdown_sent = False
         self.log = py.log.Producer("workerctl-%s" % gateway.id)
@@ -233,7 +235,7 @@ class WorkerController(object):
             py.log.setconsumer(self.log._keywords, None)
 
     def __repr__(self):
-        return "<%s %s>" % (self.__class__.__name__, self.gateway.id)
+        return "<{} {}>".format(self.__class__.__name__, self.gateway.id)
 
     @property
     def shutting_down(self):
@@ -287,17 +289,17 @@ class WorkerController(object):
         if not self._down:
             try:
                 self.sendcommand("shutdown")
-            except (IOError, OSError):
+            except OSError:
                 pass
             self._shutdown_sent = True
 
     def sendcommand(self, name, **kwargs):
         """ send a named parametrized command to the other side. """
-        self.log("sending command %s(**%s)" % (name, kwargs))
+        self.log("sending command {}(**{})".format(name, kwargs))
         self.channel.send((name, kwargs))
 
     def notify_inproc(self, eventname, **kwargs):
-        self.log("queuing %s(**%s)" % (eventname, kwargs))
+        self.log("queuing {}(**{})".format(eventname, kwargs))
         self.putevent((eventname, kwargs))
 
     def process_from_remote(self, eventcall):  # noqa too complex
@@ -319,12 +321,12 @@ class WorkerController(object):
                 return
             eventname, kwargs = eventcall
             if eventname in ("collectionstart",):
-                self.log("ignoring %s(%s)" % (eventname, kwargs))
+                self.log("ignoring {}({})".format(eventname, kwargs))
             elif eventname == "workerready":
                 self.notify_inproc(eventname, node=self, **kwargs)
             elif eventname == "workerfinished":
                 self._down = True
-                self.workeroutput = self.slaveoutput = kwargs["workeroutput"]
+                self.workeroutput = kwargs["workeroutput"]
                 self.notify_inproc("workerfinished", node=self)
             elif eventname in ("logstart", "logfinish"):
                 self.notify_inproc(eventname, node=self, **kwargs)
@@ -358,19 +360,26 @@ class WorkerController(object):
                     when=kwargs["when"],
                     item=kwargs["item"],
                 )
+            elif eventname == "warning_recorded":
+                warning_message = unserialize_warning_message(
+                    kwargs["warning_message_data"]
+                )
+                self.notify_inproc(
+                    eventname,
+                    warning_message=warning_message,
+                    when=kwargs["when"],
+                    nodeid=kwargs["nodeid"],
+                    location=kwargs["location"],
+                )
             else:
-                raise ValueError("unknown event: %s" % (eventname,))
+                raise ValueError("unknown event: {}".format(eventname))
         except KeyboardInterrupt:
             # should not land in receiver-thread
             raise
         except:  # noqa
             from _pytest._code import ExceptionInfo
 
-            # ExceptionInfo API changed in pytest 4.1
+            excinfo = ExceptionInfo.from_current()
-            if hasattr(ExceptionInfo, "from_current"):
-                excinfo = ExceptionInfo.from_current()
-            else:
-                excinfo = ExceptionInfo()
             print("!" * 20, excinfo)
             self.config.notify_exception(excinfo)
             self.shutdown()

testing/acceptance_test.py

@@ -1,10 +1,9 @@
 import os
 import re
-import sys
-import textwrap
 
 import py
 import pytest
+import xdist
 
 
 class TestDistribution:
@@ -242,22 +241,6 @@ class TestDistribution:
         result.stderr.fnmatch_lines(["--foobar=123 active! *"])
         assert dest.join(subdir.basename).check(dir=1)
 
-    def test_backward_compatibility_worker_terminology(self, testdir):
-        """Ensure that we still support "config.slaveinput" for backward compatibility (#234).
-
-        Keep in mind that removing this compatibility will break a ton of plugins and user code.
-        """
-        testdir.makepyfile(
-            """
-            def test(pytestconfig):
-                assert hasattr(pytestconfig, 'slaveinput')
-                assert hasattr(pytestconfig, 'workerinput')
-        """
-        )
-        result = testdir.runpytest("-n1")
-        result.stdout.fnmatch_lines("*1 passed*")
-        assert result.ret == 0
-
     def test_data_exchange(self, testdir):
         testdir.makeconftest(
             """
@@ -328,7 +311,7 @@ class TestDistribution:
                 time.sleep(10)
         """
         )
-        child = testdir.spawn_pytest("-n1 -v")
+        child = testdir.spawn_pytest("-n1 -v", expect_timeout=30.0)
         child.expect(".*test_sleep.*")
         child.kill(2)  # keyboard interrupt
         child.expect(".*KeyboardInterrupt.*")
@@ -590,16 +573,13 @@ def test_fixture_teardown_failure(testdir):
     assert result.ret
 
 
-def test_config_initialization(testdir, pytestconfig):
+def test_config_initialization(testdir, monkeypatch, pytestconfig):
     """Ensure workers and master are initialized consistently. Integration test for #445"""
-    if not hasattr(pytestconfig, "invocation_params"):
-        pytest.skip(
-            "requires pytest >=5.1 (config has no attribute 'invocation_params')"
-        )
     testdir.makepyfile(
         **{
             "dir_a/test_foo.py": """
-                def test_1(): pass
+                def test_1(request):
+                    assert request.config.option.verbose == 2
         """
         }
     )
@@ -610,8 +590,10 @@ def test_config_initialization(testdir, pytestconfig):
         testpaths=dir_a
     """,
     )
+    monkeypatch.setenv("PYTEST_ADDOPTS", "-v")
     result = testdir.runpytest("-n2", "-c", "myconfig.ini", "-v")
-    result.stdout.fnmatch_lines(["dir_a/test_foo.py::test_1*"])
+    result.stdout.fnmatch_lines(["dir_a/test_foo.py::test_1*", "*= 1 passed in *"])
+    assert result.ret == 0
 
 
 @pytest.mark.parametrize("when", ["setup", "call", "teardown"])
@@ -689,32 +671,6 @@ def test_skipping(testdir):
     result.stdout.fnmatch_lines(["*hello*", "*1 skipped*"])
 
 
-def test_issue34_pluginloading_in_subprocess(testdir):
-    import _pytest.hookspec
-
-    if not hasattr(_pytest.hookspec, "pytest_namespace"):
-        pytest.skip("this pytest version no longer supports pytest_namespace()")
-
-    testdir.tmpdir.join("plugin123.py").write(
-        textwrap.dedent(
-            """
-        def pytest_namespace():
-            return {'sample_variable': 'testing'}
-    """
-        )
-    )
-    testdir.makepyfile(
-        """
-        import pytest
-        def test_hello():
-            assert pytest.sample_variable == "testing"
-    """
-    )
-    result = testdir.runpytest_subprocess("-n1", "-p", "plugin123")
-    assert result.ret == 0
-    result.stdout.fnmatch_lines(["*1 passed*"])
-
-
 def test_fixture_scope_caching_issue503(testdir):
     p1 = testdir.makepyfile(
         """
@@ -792,31 +748,45 @@ def test_sub_plugins_disabled(testdir, plugin):
 
 class TestWarnings:
     @pytest.mark.parametrize("n", ["-n0", "-n1"])
-    @pytest.mark.parametrize("warn_type", ["pytest", "builtin"])
+    def test_warnings(self, testdir, n):
-    def test_warnings(self, testdir, n, request, warn_type):
-        if warn_type == "builtin":
-            warn_code = """warnings.warn(UserWarning('this is a warning'))"""
-        elif warn_type == "pytest":
-            if not hasattr(request.config, "warn"):
-                pytest.skip("config.warn has been removed in pytest 4.1")
-            warn_code = """request.config.warn('', 'this is a warning',
-                           fslocation=py.path.local())"""
-        else:
-            assert False
         testdir.makepyfile(
             """
             import warnings, py, pytest
 
             @pytest.mark.filterwarnings('ignore:config.warn has been deprecated')
             def test_func(request):
-                {warn_code}
+                warnings.warn(UserWarning('this is a warning'))
-        """.format(
+            """
-                warn_code=warn_code
-            )
         )
         result = testdir.runpytest(n)
         result.stdout.fnmatch_lines(["*this is a warning*", "*1 passed, 1 warning*"])
 
+    def test_warning_captured_deprecated_in_pytest_6(self, testdir):
+        """
+        Do not trigger the deprecated pytest_warning_captured hook in pytest 6+ (#562)
+        """
+        import _pytest.hookspec
+
+        if not hasattr(_pytest.hookspec, "pytest_warning_recorded"):
+            pytest.skip("test requires pytest 6.0+")
+
+        testdir.makeconftest(
+            """
+            def pytest_warning_captured():
+                assert False, "this hook should not be called in this version"
+        """
+        )
+        testdir.makepyfile(
+            """
+            import warnings
+            def test():
+                warnings.warn("custom warning")
+        """
+        )
+        result = testdir.runpytest("-n1")
+        result.stdout.fnmatch_lines(["* 1 passed in *"])
+        result.stdout.no_fnmatch_line("*this hook should not be called in this version")
+
     @pytest.mark.parametrize("n", ["-n0", "-n1"])
     def test_custom_subclass(self, testdir, n):
         """Check that warning subclasses that don't honor the args attribute don't break
@@ -863,9 +833,6 @@ class TestWarnings:
         """Check that warnings with unserializable _WARNING_DETAILS are
         handled correctly (#379).
         """
-        if sys.version_info[0] < 3:
-            # The issue is only present in Python 3 warnings
-            return
         testdir.makepyfile(
             """
             import warnings, pytest
@@ -1066,6 +1033,29 @@ def test_worker_id_fixture(testdir, n):
         assert worker_ids == {"gw0", "gw1"}
 
 
+@pytest.mark.parametrize("n", [0, 2])
+def test_testrun_uid_fixture(testdir, n):
+    import glob
+
+    f = testdir.makepyfile(
+        """
+        import pytest
+        @pytest.mark.parametrize("run_num", range(2))
+        def test_testrun_uid1(testrun_uid, run_num):
+            with open("testrun_uid%s.txt" % run_num, "w") as f:
+                f.write(testrun_uid)
+    """
+    )
+    result = testdir.runpytest(f, "-n%d" % n)
+    result.stdout.fnmatch_lines("* 2 passed in *")
+    testrun_uids = set()
+    for fname in glob.glob(str(testdir.tmpdir.join("*.txt"))):
+        with open(fname) as f:
+            testrun_uids.add(f.read().strip())
+    assert len(testrun_uids) == 1
+    assert len(testrun_uids.pop()) == 32
+
+
 @pytest.mark.parametrize("tb", ["auto", "long", "short", "no", "line", "native"])
 def test_error_report_styles(testdir, tb):
     testdir.makepyfile(
@@ -1358,7 +1348,7 @@ def parse_tests_and_workers_from_output(lines):
             r"""
             \[(gw\d)\]  # worker
             \s*
-            (?:\[\s*\d+%\])? # progress indicator (pytest >=3.3)
+            (?:\[\s*\d+%\])? # progress indicator
             \s(.*?)     # status string ("PASSED")
             \s(.*::.*)  # nodeid
         """,
@@ -1377,3 +1367,39 @@ def get_workers_and_test_count_by_prefix(prefix, lines, expected_status="PASSED"
         if expected_status == status and nodeid.startswith(prefix):
             result[worker] = result.get(worker, 0) + 1
     return result
+
+
+class TestAPI:
+    @pytest.fixture
+    def fake_request(self):
+        class FakeOption:
+            def __init__(self):
+                self.dist = "load"
+
+        class FakeConfig:
+            def __init__(self):
+                self.workerinput = {"workerid": "gw5"}
+                self.option = FakeOption()
+
+        class FakeRequest:
+            def __init__(self):
+                self.config = FakeConfig()
+
+        return FakeRequest()
+
+    def test_is_xdist_worker(self, fake_request):
+        assert xdist.is_xdist_worker(fake_request)
+        del fake_request.config.workerinput
+        assert not xdist.is_xdist_worker(fake_request)
+
+    def test_is_xdist_master(self, fake_request):
+        assert not xdist.is_xdist_master(fake_request)
+        del fake_request.config.workerinput
+        assert xdist.is_xdist_master(fake_request)
+        fake_request.config.option.dist = "no"
+        assert not xdist.is_xdist_master(fake_request)
+
+    def test_get_xdist_worker_id(self, fake_request):
+        assert xdist.get_xdist_worker_id(fake_request) == "gw5"
+        del fake_request.config.workerinput
+        assert xdist.get_xdist_worker_id(fake_request) == "master"

testing/conftest.py

@@ -1,20 +1,9 @@
-import six
 import py
 import pytest
 import execnet
 
 pytest_plugins = "pytester"
 
-if six.PY2:
-
-    @pytest.fixture(scope="session", autouse=True)
-    def _ensure_imports():
-        # we import some modules because pytest-2.8's testdir fixture
-        # will unload all modules after each test and this cause
-        # (unknown) problems with execnet.Group()
-        execnet.Group
-        execnet.makegateway
-
 
 @pytest.fixture(autouse=True)
 def _divert_atexit(request, monkeypatch):
@@ -22,12 +11,16 @@ def _divert_atexit(request, monkeypatch):
 
     finalizers = []
 
-    def finish():
+    def fake_register(func, *args, **kwargs):
-        while finalizers:
+        finalizers.append((func, args, kwargs))
-            finalizers.pop()()
 
-    monkeypatch.setattr(atexit, "register", finalizers.append)
+    monkeypatch.setattr(atexit, "register", fake_register)
-    request.addfinalizer(finish)
+
+    yield
+
+    while finalizers:
+        func, args, kwargs = finalizers.pop()
+        func(*args, **kwargs)
 
 
 def pytest_addoption(parser):

testing/test_dsession.py

@@ -203,7 +203,7 @@ class TestLoadScheduling:
         different test ids are collected by workers.
         """
 
-        class CollectHook(object):
+        class CollectHook:
             """
             Dummy hook that stores collection reports.
             """

testing/test_looponfail.py

@@ -284,7 +284,7 @@ class TestFunctional:
         )
         # p = testdir.mkdir("sub").join(p1.basename)
         # p1.move(p)
-        child = testdir.spawn_pytest("-f %s --traceconfig" % p)
+        child = testdir.spawn_pytest("-f %s --traceconfig" % p, expect_timeout=30.0)
         child.expect("def test_one")
         child.expect("x == 1")
         child.expect("1 failed")
@@ -311,7 +311,7 @@ class TestFunctional:
                 pass
         """
         )
-        child = testdir.spawn_pytest("-f %s" % p)
+        child = testdir.spawn_pytest("-f %s" % p, expect_timeout=30.0)
         child.expect("1 xpass")
         # child.expect("### LOOPONFAILING ####")
         child.expect("waiting for changes")

testing/test_newhooks.py

@@ -15,7 +15,7 @@ class TestHooks:
 
     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)
+        with xdist contain "node", "nodeid", "worker_id", and "testrun_uid" attributes. (#8)
         """
         testdir.makeconftest(
             """
@@ -23,20 +23,24 @@ class TestHooks:
                 if hasattr(report, 'node'):
                     if report.when == "call":
                         workerid = report.node.workerinput['workerid']
+                        testrunuid = report.node.workerinput['testrunuid']
                         if workerid != report.worker_id:
                             print("HOOK: Worker id mismatch: %s %s"
                                    % (workerid, report.worker_id))
+                        elif testrunuid != report.testrun_uid:
+                            print("HOOK: Testrun uid mismatch: %s %s"
+                                   % (testrunuid, report.testrun_uid))
                         else:
-                            print("HOOK: %s %s"
+                            print("HOOK: %s %s %s"
-                                   % (report.nodeid, report.worker_id))
+                                   % (report.nodeid, report.worker_id, report.testrun_uid))
         """
         )
         res = testdir.runpytest("-n1", "-s")
         res.stdout.fnmatch_lines(
             [
-                "*HOOK: test_runtest_logreport.py::test_a gw0*",
+                "*HOOK: test_runtest_logreport.py::test_a gw0 *",
-                "*HOOK: test_runtest_logreport.py::test_b gw0*",
+                "*HOOK: test_runtest_logreport.py::test_b gw0 *",
-                "*HOOK: test_runtest_logreport.py::test_c gw0*",
+                "*HOOK: test_runtest_logreport.py::test_c gw0 *",
                 "*3 passed*",
             ]
         )

testing/test_plugin.py

@@ -1,7 +1,11 @@
+from contextlib import suppress
+
 import py
 import execnet
 from xdist.workermanage import NodeManager
 
+import pytest
+
 
 def test_dist_incompatibility_messages(testdir):
     result = testdir.runpytest("--pdb", "--looponfail")
@@ -38,6 +42,11 @@ def test_auto_detect_cpus(testdir, monkeypatch):
     import os
     from xdist.plugin import pytest_cmdline_main as check_options
 
+    with suppress(ImportError):
+        import psutil
+
+        monkeypatch.setattr(psutil, "cpu_count", lambda logical=True: None)
+
     if hasattr(os, "sched_getaffinity"):
         monkeypatch.setattr(os, "sched_getaffinity", lambda _pid: set(range(99)))
     elif hasattr(os, "cpu_count"):
@@ -51,19 +60,48 @@ def test_auto_detect_cpus(testdir, monkeypatch):
     assert config.getoption("numprocesses") == 2
 
     config = testdir.parseconfigure("-nauto")
+    check_options(config)
     assert config.getoption("numprocesses") == 99
 
     config = testdir.parseconfigure("-nauto", "--pdb")
     check_options(config)
     assert config.getoption("usepdb")
     assert config.getoption("numprocesses") == 0
+    assert config.getoption("dist") == "no"
 
     monkeypatch.delattr(os, "sched_getaffinity", raising=False)
     monkeypatch.setenv("TRAVIS", "true")
     config = testdir.parseconfigure("-nauto")
+    check_options(config)
     assert config.getoption("numprocesses") == 2
 
 
+def test_auto_detect_cpus_psutil(testdir, monkeypatch):
+    from xdist.plugin import pytest_cmdline_main as check_options
+
+    psutil = pytest.importorskip("psutil")
+
+    monkeypatch.setattr(psutil, "cpu_count", lambda logical=True: 42)
+
+    config = testdir.parseconfigure("-nauto")
+    check_options(config)
+    assert config.getoption("numprocesses") == 42
+
+
+def test_hook_auto_num_workers(testdir, monkeypatch):
+    from xdist.plugin import pytest_cmdline_main as check_options
+
+    testdir.makeconftest(
+        """
+        def pytest_xdist_auto_num_workers():
+            return 42
+    """
+    )
+    config = testdir.parseconfigure("-nauto")
+    check_options(config)
+    assert config.getoption("numprocesses") == 42
+
+
 def test_boxed_with_collect_only(testdir):
     from xdist.plugin import pytest_cmdline_main as check_options
 
@@ -95,6 +133,18 @@ def test_dsession_with_collect_only(testdir):
     assert not config.pluginmanager.hasplugin("dsession")
 
 
+def test_testrunuid_provided(testdir):
+    config = testdir.parseconfigure("--testrunuid", "test123", "--tx=popen")
+    nm = NodeManager(config)
+    assert nm.testrunuid == "test123"
+
+
+def test_testrunuid_generated(testdir):
+    config = testdir.parseconfigure("--tx=popen")
+    nm = NodeManager(config)
+    assert len(nm.testrunuid) == 32
+
+
 class TestDistOptions:
     def test_getxspecs(self, testdir):
         config = testdir.parseconfigure("--tx=popen", "--tx", "ssh=xyz")

testing/test_remote.py

@@ -2,12 +2,13 @@ import py
 import pprint
 import pytest
 import sys
+import uuid
 
 from xdist.workermanage import WorkerController
 import execnet
 import marshal
 
-from six.moves.queue import Queue
+from queue import Queue
 
 WAIT_TIMEOUT = 10.0
 
@@ -25,7 +26,7 @@ class EventCall:
         self.name, self.kwargs = eventcall
 
     def __str__(self):
-        return "<EventCall %s(**%s)>" % (self.name, self.kwargs)
+        return "<EventCall {}(**{})>".format(self.name, self.kwargs)
 
 
 class WorkerSetup:
@@ -44,6 +45,7 @@ class WorkerSetup:
         putevent = self.use_callback and self.events.put or None
 
         class DummyMananger:
+            testrunuid = uuid.uuid4().hex
             specs = [0, 1]
 
         self.slp = WorkerController(DummyMananger, self.gateway, config, putevent)
@@ -59,7 +61,7 @@ class WorkerSetup:
             ev = EventCall(data)
             if name is None or ev.name == name:
                 return ev
-            print("skipping %s" % (ev,))
+            print("skipping {}".format(ev))
 
     def sendcommand(self, name, **kwargs):
         self.slp.sendcommand(name, **kwargs)
@@ -220,6 +222,7 @@ def test_remote_env_vars(testdir):
         """
         import os
         def test():
+            assert len(os.environ['PYTEST_XDIST_TESTRUNUID']) == 32
             assert os.environ['PYTEST_XDIST_WORKER'] in ('gw0', 'gw1')
             assert os.environ['PYTEST_XDIST_WORKER_COUNT'] == '2'
     """

testing/test_workermanage.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import py
 import pytest
 import textwrap
@@ -35,7 +34,7 @@ def mysetup(tmpdir):
 
 @pytest.fixture
 def workercontroller(monkeypatch):
-    class MockController(object):
+    class MockController:
         def __init__(self, *args):
             pass
 
@@ -168,7 +167,7 @@ class TestNodeManager:
         # assert nodemanager.config.topdir == source == config.topdir
         nodemanager.makegateways()
         nodemanager.rsync_roots()
-        p, = nodemanager.gwmanager.multi_exec(
+        (p,) = nodemanager.gwmanager.multi_exec(
             "import os ; channel.send(os.getcwd())"
         ).receive_each()
         p = py.path.local(p)
@@ -197,6 +196,25 @@ class TestNodeManager:
             assert dest.join("dir1", "dir2", "hello").check()
             nodemanager.teardown_nodes()
 
+    @pytest.mark.parametrize(
+        "flag, expects_report", [("-q", False), ("", False), ("-v", True)]
+    )
+    def test_rsync_report(
+        self, testdir, mysetup, workercontroller, capsys, flag, expects_report
+    ):
+        source, dest = mysetup.source, mysetup.dest
+        dir1 = mysetup.source.mkdir("dir1")
+        args = "--tx", "popen//chdir=%s" % dest, "--rsyncdir", dir1, source
+        if flag:
+            args += (flag,)
+        nodemanager = NodeManager(testdir.parseconfig(*args))
+        nodemanager.setup_nodes(None)  # calls .rsync_roots()
+        out, _ = capsys.readouterr()
+        if expects_report:
+            assert "<= pytest/__init__.py" in out
+        else:
+            assert "<= pytest/__init__.py" not in out
+
     def test_init_rsync_roots(self, testdir, mysetup, workercontroller):
         source, dest = mysetup.source, mysetup.dest
         dir2 = source.ensure("dir1", "dir2", dir=1)
@@ -269,5 +287,5 @@ class TestNodeManager:
         reprec = testdir.inline_run(
             "-d", "--rsyncdir=%s" % testdir.tmpdir, "--tx", specssh, testdir.tmpdir
         )
-        rep, = reprec.getreports("pytest_runtest_logreport")
+        (rep,) = reprec.getreports("pytest_runtest_logreport")
         assert rep.passed

tox.ini

@@ -1,21 +1,28 @@
 [tox]
 envlist=
   linting
-  py{27,34,35,36,37,38}-pytestlatest
+  py{35,36,37,38,39}-pytestlatest
-  py38-pytest{master,features}
+  py38-pytestmaster
+  py38-psutil
 
 [testenv]
-passenv = USER USERNAME
 extras = testing
 deps =
   pytestlatest: pytest
   pytestmaster: git+https://github.com/pytest-dev/pytest.git@master
-  pytestfeatures: git+https://github.com/pytest-dev/pytest.git@features
 commands=
   pytest {posargs}
 
+[testenv:py38-psutil]
+extras =
+  testing
+  psutil
+deps = pytest
+commands =
+  pytest {posargs:-k psutil}
+
 [testenv:linting]
-skipsdist = True
+skip_install = True
 usedevelop = True
 deps =
   pre-commit
@@ -29,9 +36,9 @@ skipsdist = True
 usedevelop = True
 passenv = *
 deps =
-    towncrier
+  towncrier
 commands =
-    towncrier --version {posargs} --yes
+  towncrier --version {posargs} --yes
 
 [pytest]
 addopts = -ra