FYI I'm still affected by this issue on up-to-date buster. I have been
using the following workaround in my code to recast the constants as ints
but I think we probably want to look at backporting whatever fix is in
later (bullseye?) releases:
# Ugly workaround for #938965. Brute force conversion of constants to
# ints from their representations:
for k, v in alsaseq.__dict__.items():
if k.startswith("SEQ_"):
try:
alsaseq.__dict__[k] = int(repr(v).split("(")[1][:-1], 16)
except:
pass
On Fri, Jan 08, 2021 at 09:58:12AM +0000, Ben Bell wrote:
> Package: python-pyalsa
> Version: 1.1.6-1+b1
> Severity: important
>
> pyalsa version 1.1.6 appears to have introduced a bug when setting
> sysex data in events. Rather than the string of bytes provided, it
> instead produces an equal length string but containing the last byte
> over and over:
>
> With 1.0.26:
> Data set as [240, 126, 127, 6, 1, 247]
> Data retrieved as {'ext': [240, 126, 127, 6, 1, 247]}
>
> With 1.1.6:
> Data set as [240, 126, 127, 6, 1, 247]
> Data retrieved as {'ext': [247, 247, 247, 247, 247, 247]}
>
> Reproducer:
> #!/usr/bin/python
> #
>
> from __future__ import print_function
> import pyalsa.alsaseq as alsaseq
>
> seq = alsaseq.Sequencer()
> ne = alsaseq.SeqEvent(alsaseq.SEQ_EVENT_SYSEX)
>
> data = [0xf0, 0x7e, 0x7f, 0x06, 0x01, 0xf7]
>
> ne.set_data({"ext": data})
> print("Data set as", data)
> print("Data retrieved as", ne.get_data())
>
> This bug is in python-1.1.6-1+b1, which is the latest python2
> version. There appears to be another bug (#938965) affecting buster
> which stops me testing with python3:
>
> bjb@rowlf [96] python3 test-alsa-sysex-event.py
> Traceback (most recent call last):
> File "test-alsa-sysex-event.py", line 8, in <module>
> ne = alsaseq.SeqEvent(alsaseq.SEQ_EVENT_SYSEX)
> OverflowError: Python int too large to convert to C long
>
> ...but if I hack around that it's reproducible in python3 too:
> bjb@rowlf [99] python3 test-alsa-sysex-event.py
> Data set as [240, 126, 127, 6, 1, 247]
> Data retrieved as {'ext': [247, 247, 247, 247, 247, 247]}
>
> At the least we might need a newer version (from bullseye -- untested by
> me) backported to buster.
>
> bjb
>
>
> -- System Information:
> Debian Release: 10.6
> APT prefers stable
> APT policy: (500, 'stable')
> Architecture: amd64 (x86_64)
> Foreign Architectures: i386
>
> Kernel: Linux 5.10.0-rc5-rt10-rt (SMP w/4 CPU cores; PREEMPT)
> Kernel taint flags: TAINT_UNSIGNED_MODULE
> Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8),
> LANGUAGE=en_GB:en (charmap=UTF-8)
> Shell: /bin/sh linked to /bin/dash
> Init: systemd (via /run/systemd/system)
> LSM: AppArmor: enabled
>
> Versions of packages python-pyalsa depends on:
> ii libasound2 1.1.8-1
> ii libc6 2.28-10
> ii python 2.7.16-1
>
> python-pyalsa recommends no packages.
>
> python-pyalsa suggests no packages.
>
> -- no debconf information
