Do not change PYTHONPATH or sys.path on workers

Fix #376

Author: nicoddemus

changelog/376.feature.rst

@@ -0,0 +1,3 @@
+The current directory is no longer added ``sys.path`` on workers.
+
+This behavior is surprising because it makes xdist runs and non-xdist runs to potentially behave differently.

xdist/remote.py

@@ -251,17 +251,12 @@ def remote_initconfig(option_dict, args):
 
 
 if __name__ == "__channelexec__":
+    import py
+
     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
-    import py
 
     config = remote_initconfig(option_dict, args)
     config._parser.prog = os.path.basename(workerinput["mainargv"][0])