fix various flakes issues and add "flakes" to tox tests

xdist/dsession.py

@@ -1,4 +1,3 @@
-import sys
 import difflib
 
 import pytest
@@ -295,7 +294,7 @@ class DSession:
             self.slave_errordown(node, "keyboard-interrupt")
             return
         crashitem = self.sched.remove_node(node)
-        #assert not crashitem, (crashitem, node)
+        assert not crashitem, (crashitem, node)
         if self.shuttingdown and not self.sched.hasnodes():
             self.session_finished = True
 

xdist/looponfail.py

@@ -87,7 +87,7 @@ class RemoteControl(object):
         result = self.runsession()
         failures, reports, collection_failed = result
         if collection_failed:
-            reports = ["Collection failed, keeping previous failure set"]
+            pass # "Collection failed, keeping previous failure set"
         else:
             uniq_failures = []
             for failure in failures:
@@ -109,7 +109,6 @@ def repr_pytest_looponfailinfo(failreports, rootdirs):
 
 def init_slave_session(channel, args, option_dict):
     import os, sys
-    import py
     outchannel = channel.gateway.newchannel()
     sys.stdout = sys.stderr = outchannel.makefile('w')
     channel.send(outchannel)

xdist/remote.py

@@ -128,6 +128,7 @@ def remote_initconfig(option_dict, args):
 
 
 if __name__ == '__channelexec__':
+    channel = channel  # noqa
     # python3.2 is not concurrent import safe, so let's play it safe
     # https://bitbucket.org/hpk42/pytest/issue/347/pytest-xdist-and-python-32
     if sys.version_info[:2] == (3,2):