psychopy modules and sounddevice (error message after finishing script)

[piotx]

Hi,

when loading the sounddevice module after the visual or event module from psychopy I get an error message when finishing or quitting the script (sys.exit()):

*** Error in `python': free(): invalid pointer: 0x00007fc9289b8540 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x6ef45)[0x7fc92868af45]
/lib/x86_64-linux-gnu/libc.so.6(+0x746b6)[0x7fc9286906b6]
/lib/x86_64-linux-gnu/libc.so.6(+0x74e9e)[0x7fc928690e9e]
/lib/x86_64-linux-gnu/libc.so.6(fclose+0x103)[0x7fc9286815f3]
/usr/lib/x86_64-linux-gnu/libopenal.so.1(+0xae13)[0x7fc909480e13]
/lib64/ld-linux-x86-64.so.2(+0xf9b7)[0x7fc9295109b7]
/lib/x86_64-linux-gnu/libc.so.6(+0x35b78)[0x7fc928651b78]
/lib/x86_64-linux-gnu/libc.so.6(+0x35bc5)[0x7fc928651bc5]
python[0x52540f]
python[0x52288d]
python(PyErr_PrintEx+0x36)[0x522176]
python[0x42ec24]
python(Py_Main+0x6c1)[0x49dc51]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7fc92863c730]
python(_start+0x29)[0x49d4a9]
======= Memory map: ========
00400000-006eb000 r-xp 00000000 08:03 4982615                            /usr/bin/python2.7
008eb000-008ed000 r--p 002eb000 08:03 4982615                            /usr/bin/python2.7
008ed000-00964000 rw-p 002ed000 08:03 4982615                            /usr/bin/python2.7
00964000-00987000 rw-p 00000000 00:00 0 
022c3000-07fa3000 rw-p 00000000 00:00 0                                  [heap]
7fc8ec000000-7fc8ec021000 rw-p 00000000 00:00 0 
...

minimal example causing the error:

from psychopy import event
import sounddevice

this is fine:

import sounddevice
from psychopy import event

The workaround for now is just to import sounddevice before the psychopy modules.

I'm running debian unstable with psychopy '1.83.04'

Do you have any clue, what could be the reason for this. Is it a sounddevice or psychopy issue? I've posted this to the psychopy forum as well, in case they have an idea about it.

best wishes
Piotr

[piotx]

Jon from psychopy said, that it might have to do with the pyglet module. It doesn't go along too well with other modules, so maybe this issue can be closed..

[mgeier]

Hmmm, that's a strange error.

It seems to be somehow caused by assigning to stderr in _ignore_stderr().

When you remove the call to _ignore_stderr(), it should work.

Any ideas how to properly fix this?

[piotx]

thanks, that fixed it for now

[mgeier]

Good to know that the work-around works. It would still be nice to find the real cause of the problem ...