Unable to use subprocess.check_output with sounddevice 0.4.6

[micgrzyw]

Unable to call subprocess.check_output after importing sounddevice 0.4.6
Output error: [WinError 50] The request is not supported

System: Windows 10 and 11
Python: 3.11.2
sounddevice 0.4.6
pyinstaller 5.9.0

Easy reproduction

1. Write script aaa.py

import subprocess
output = subprocess.check_output("ECHO before import", shell=True)
print(output)
import sounddevice
output = subprocess.check_output("ECHO after import", shell=True)
print(output)

2. Build using pyinstaller 5.9.0

python -m PyInstaller --onefile aaa.py

aaa.exe
> b'before import\r\n'
> Traceback (most recent call last):
> File "aaa.py", line 7, in <module>
> File "subprocess.py", line 466, in check_output
> File "subprocess.py", line 548, in run
> File "subprocess.py", line 892, in __init__
> File "subprocess.py", line 1378, in _get_handles
> File "subprocess.py", line 1387, in _make_inheritable
> OSError: [WinError 50] The request is not supported

[mgeier]

Thanks for the report!

Can you please try it with an older sounddevice version, e.g. 0.4.5?
Maybe #444 caused the problem ...

And could you try to somehow get a traceback to see where the OSError is happening?

[micgrzyw]

Hi :)

Yes, 0.4.5 works fine. #444 indeed looks like a root cause

Is this traceback sufficient?

Traceback (most recent call last):
  File "aaa.py", line 7, in <module>
  File "subprocess.py", line 466, in check_output
  File "subprocess.py", line 548, in run
  File "subprocess.py", line 892, in __init__
  File "subprocess.py", line 1378, in _get_handles
  **File "subprocess.py", line 1387, in _make_inheritable**
OSError: [WinError 50] The request is not supported

[mgeier]

Is this traceback sufficient?

It's not sufficient for me to understand the problem, since it doesn't point to the offending code in sounddevice.py.

I guess one way to find out which line causes the problem would be to deactivate the changes from #444 line-by-line until the exception doesn't happen anymore.

[pozgax]

I observed a similar case - such an error is shown in version 0.4.6, but after reverting the import to 0.4.5 we do not observe the error anymore.

[micgrzyw]

Hi @mgeier!

This issue is observed by more than me in our project. Yes, everything works with sounddevice 0.4.5, however we would like to unblock using 0.4.6 and future updates.

Change #444 blocks using a subprocess module in built application on Windows platforms as described above. If I revert this change manually, then the problem does not reproduce, so it is clearly a rootcause. However I wouldn't want to make a dirty changes in 3rd party component in our project.

Is it possible to revert this change and make a new release? Please let me know if there are any plans to fix this issue.

And many thanks for your support!

[ndahn]

Still seems to be an issue sadly :/

[mgeier]

Feel free to do more research and experimentation and provide an explanation/solution/work-around.

For starters, you could create a MRE (i.e. without using sounddevice) and ask an LLM why it doesn't work.

[ndahn]

I'll look into it over the next few weeks, sounddevice is a central part of my app ~

[ndahn]

After a short claude session this is the underlying issue:

The root cause is that sounddevice's _initialize() manipulates file descriptor 2 (stderr) using os.dup/os.dup2 to temporarily redirect it to /dev/null during PortAudio initialization.

On Windows in a PyInstaller binary, stderr is not a real console handle. This causes the dup/dup2 operations to corrupt the Windows CRT's internal file descriptor / handle inheritance table. Once corrupted, any subsequent subprocess call that touches stdout/stderr handle inheritance fails with WinError 50: the request is not supported.

I have created a PR which fixes this (and have confirmed it works :) ).
Do you think you will make a new release anytime soon, or should I keep a monkey patch in my app?