[Windows] Basic run operation uses wrong environment

[jaraco]

Given this simple test:

def test_run(virtualenv):
    import sys
    cmd = ['python', '-c', 'import sys; print(sys.prefix)']
    res = virtualenv.run(cmd, capture=True, text=True).strip()
    assert sys.prefix not in res

This test runs a command in the virtualenv emitting the sys.prefix and expects it not to be the sys.prefix of the test runner.

It passes on Unix-like OSs, but fails on Windows with this trace:

PS C:\Users\jaraco\draft> env/Scripts/pytest '\\vmware-host\shared folders\home\draft\virtualenv-run.py'
============================= test session starts =============================
platform win32 -- Python 3.8.3, pytest-6.0.1, py-1.9.0, pluggy-0.13.1
rootdir: \\vmware-host\shared folders\home\draft
plugins: shutil-1.7.0, virtualenv-1.7.0, xonsh-0.9.18
collected 1 item

\\vmware-host\shared folders\home\draft\virtualenv-run.py F              [100%]

================================== FAILURES ===================================
__________________________________ test_run ___________________________________

virtualenv = <pytest_virtualenv.VirtualEnv object at 0x00000222DB0C6E50>

    def test_run(virtualenv):
        import sys
        cmd = ['python', '-c', 'import sys; print(sys.prefix)']
        res = virtualenv.run(cmd, capture=True, text=True).strip()
>       assert sys.prefix not in res
E       AssertionError: assert 'c:\\users\\...\\draft\\env' not in 'c:\\users\\...\\draft\\env'
E         'c:\\users\\jaraco\\draft\\env' is contained here:
E           c:\users\jaraco\draft\env

\\vmware-host\shared folders\home\draft\virtualenv-run.py:5: AssertionError
---------------------------- Captured stdout setup ----------------------------
created virtual environment CPython3.8.3.final.0-64 in 703ms

  creator CPython3Windows(dest=C:\Users\jaraco\AppData\Local\Temp\tmppmdecetw\.env, clear=False, global=False)

  seeder FromAppData(download=False, pip=bundle, setuptools=bundle, wheel=bundle, via=copy, app_data_dir=C:\Users\jaraco\AppData\Local\pypa\virtualenv)

    added seed packages: pip==20.2.1, setuptools==49.2.1, wheel==0.34.2

  activators BashActivator,BatchActivator,FishActivator,PowerShellActivator,PythonActivator,XonshActivator

=========================== short test summary info ===========================
FAILED \\vmware-host\shared folders\home\draft\virtualenv-run.py::test_run - ...
============================== 1 failed in 1.23s ==============================