xdist adds current directory to sys.path

[ndevenish]

With 1.26.1.

import sys

def test_path():
    assert "" not in sys.path

$ pytest test_path.py
<OK>
$ pytest test_path.py -n 1
E     AssertionError....

Obviously this can cause problems/change behaviour depending on where you are running the tests from.

Possibly related to #376?

[ndevenish]

In fact, the diagnosis on my end is almost exactly the same as #376 - the second entry changes from the python executable dir to the empty string. So I guess a regression rather than a new bug?

[nicoddemus]

Hi @ndevenish,

Are you on Python 2.7? I ask because you might have the same issue as #414.

[ndevenish]

Yes, Initially, but the error (path turning into '' therefore current directory import) happens in 3 also, either a virtualenv or a simple docker:

FROM python:3
RUN pip3 install -U pytest-xdist==1.26.1
RUN printf "import sys\ndef test_path():\n  assert not '' in sys.path\n" >> test_path.py
RUN pytest test_path.py
RUN pytest test_path.py -n 1

So, no conftest.py or site.py or anything interfering. Results in:

Step 4/5 : RUN pytest test_path.py
============================= test session starts ==============================
platform linux -- Python 3.7.2, pytest-4.3.1, py-1.8.0, pluggy-0.9.0
rootdir: /, inifile:
plugins: xdist-1.26.1, forked-1.0.2
collected 1 item

test_path.py .                                                           [100%]

=========================== 1 passed in 0.01 seconds ===========================

Step 5/5 : RUN pytest test_path.py -n 1
============================= test session starts ==============================
platform linux -- Python 3.7.2, pytest-4.3.1, py-1.8.0, pluggy-0.9.0
rootdir: /, inifile:
plugins: xdist-1.26.1, forked-1.0.2
gw0 I
gw0 [1]

F                                                                        [100%]
=================================== FAILURES ===================================
__________________________________ test_path ___________________________________
[gw0] linux -- Python 3.7.2 /usr/local/bin/python

    def test_path():
>     assert not '' in sys.path
E     AssertionError: assert not '' in ['/', '', '/usr/local/lib/python37.zip', '/usr/local/lib/python3.7', '/usr/local/lib/python3.7/lib-dynload', '/usr/local/lib/python3.7/site-packages']
E      +  where ['/', '', '/usr/local/lib/python37.zip', '/usr/local/lib/python3.7', '/usr/local/lib/python3.7/lib-dynload', '/usr/local/lib/python3.7/site-packages'] = sys.path

test_path.py:3: AssertionError
=========================== 1 failed in 0.32 seconds ===========================
The command '/bin/sh -c pytest test_path.py -n 1' returned a non-zero code: 1

It looks to be the same root cause though.

[graingert]

the problem is the way execnet runs python, vs setuptools console_scripts entry_points

when you run with /home/graingert/projects/pytest-bdd/.tox/py39-pytestlatest-xdist/bin/pytest the sys.path is set to:

E         +  '/home/graingert/projects/pytest-bdd/.tox/py39-pytestlatest-xdist/bin',
E         +  '/usr/lib/python39.zip',
E         +  '/usr/lib/python3.9',
E         +  '/usr/lib/python3.9/lib-dynload',
E         +  '/home/graingert/projects/pytest-bdd/.tox/py39-pytestlatest-xdist/lib/python3.9/site-packages',

however execnet runs with

/home/graingert/projects/pytest-bdd/.tox/py39-pytestlatest-xdist/bin/python

and so the path is:

['', '/usr/lib/python39.zip', '/usr/lib/python3.9', '/usr/lib/python3.9/lib-dynload', '/home/graingert/projects/pytest-bdd/.tox/py39-pytestlatest-xdist/lib/python3.9/site-packages']