spawn hangs when run in virtual environment

[SullivanChrisJ]

Describe the bug

When run in cmd window, the spawn command works fine, but if in a virtual environment, it hangs forever.

To Reproduce

This works

C:\Users\csullivan\Documents\Projects\netlog>python
Python 3.9.5 (tags/v3.9.5:0a7dcbd, May  3 2021, 17:27:52) [MSC v.1928 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from wexpect import spawn
>>> spawn("cmd.exe")
<wexpect.host.SpawnPipe object at 0x0000019F7040DBB0>
>>>

but this does not return from spawn.

(env) C:\Users\csullivan\Documents\Projects\netlog>python
Python 3.9.5 (tags/v3.9.5:0a7dcbd, May  3 2021, 17:27:52) [MSC v.1928 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from wexpect import spawn
>>> spawn("cmd.exe")

Expected behavior
I would expect identical behaviour in a Python Virtual Environment if software versions are the same, which they are.

Environment:
Microsoft Windows 10 Pro 10.0.19043 Build 19043
Dell Latitude 7490
Python 3.9.5
wexpect 4.0.0

Additional context
Submitted this as a question to Stack Overflow.

[raczben]

Hi,

Check out #26
https://stackoverflow.com/q/61290972/2506522

https://bugs.python.org/issue38905

[SullivanChrisJ]

I am using virtualenv, not venv. The python -c "import sys; print(sys.executable)" test shows the virtualenv version of Python, not the system-wide one. Using subprocess directly, Popen returns an object as expected. Sorry I didn't make that clear on the OP, I'd forgotten about venv.

[raczben]

Hi,

As @ddeel has found in this comment:

Release 20.0.34 that says "Align with venv module when creating virtual environments with builtin creator on Windows 3.7 and later"

This means that the now the same thing can happen both in venv and virtualenv.

The 850eece shows a way to solve this issue in all virtualenv. This implementation does not uses the child process' pid to identify the pip.

[ScriptPup]

Was a solution or workaround for this ever implemented? I just tried building from source in case it was only in the dev build, but I'm still unable to use wexpect within a virtual environment.