Bug#1107283: mcomix fails to start

[Fenix F.]

This is the fix from upstream:

---
--- a/mcomix/__main__.py
+++ b/mcomix/__main__.py
@@ -21,10 +21,10 @@


 def main() -> None:
-mp.freeze_support()
-mp.set_start_method('spawn')
 run()


 if __name__ == '__main__':
+mp.freeze_support()
+mp.set_start_method('spawn')
 main()
---

https://sourceforge.net/p/mcomix/git/ci/a4092eb4f2927ce5d600444d0b10c308148ca34d/

It is not versioned yet.

Bug#1107283: mcomix fails to start

[Olivier Allard-Jacquin]

Hi,

I have the same issue with mcomix = 3.1.0-1

Issue look like appear after python3 upgrade 3.13.3-1 -> 3.13.5-1.


Matohara San's pach (thanks !!!) works also for me.


Edit your /usr/lib/python3/dist-packages/mcomix/__main__.py

and change:
mp.set_start_method('spawn')

to:
try:
mp.set_start_method('spawn')
except RuntimeError:
pass

Be careful for tabs, because Python is tab sensitive.

Best regards,
Olivier

Bug#1107283: mcomix fails to start

[Dominique Dumont]

Hi 

I have the same issue:

$ python3 --version
Python 3.13.5
$ mcomix
Traceback (most recent call last):
  File "/usr/bin/mcomix", line 8, in 
sys.exit(main())
 ^^
  File "/usr/lib/python3/dist-packages/mcomix/__main__.py", line 25, in main
mp.set_start_method('spawn')
~~~^
  File "/usr/lib/python3.13/multiprocessing/context.py", line 247, in 
set_start_method
raise RuntimeError('context has already been set')
RuntimeError: context has already been set

I suggest you ask for help on debian-python mailing list.

All the best

Bug#1107283: 回复：Bug#1107283: mcomix fails to start

[Tatsuki Sugiura]

Dear Maintainer,

I have the same issue.
The patch from Kenichiro works for me.

> even this line of code is not included in mcomix itself.

Oh? The file is placed in 
/usr/lib/python3/dist-packages/mcomix/__main__.py on my environment.


It seems to come from;
https://sources.debian.org/src/mcomix/3.1.0-1/mcomix/__main__.py/

Thanks,

Bug#1107283: 回复：Bug#1107283: mcomix fails to start

[Wei Zhou]

> $ mcomix
> Traceback (most recent call last):
>   File "/usr/bin/mcomix", line 5, in 

Bug#1107283: mcomix fails to start

[Kenichiro Matohara]

Package: mcomix
Version: 3.1.0-1
Severity: normal

Dear Maintainer,

Probably after a recent Python update mcomix is ​​failing to start.

$ mcomix
Traceback (most recent call last):
  File "/usr/bin/mcomix", line 5, in 
from mcomix.__main__ import main
  File "/usr/lib/python3/dist-packages/mcomix/__main__.py", line 29, in 
set_start_method('forkserver', force=True)

NameError: name 'set_start_method' is not defined



I was able to get it to work by modifying it as follows.
However, I don't understand Python so I don't know if this is the 
correct modification. Just for reference.



$ diff -u ./usr/lib/python3/dist-packages/mcomix/__main__.py 
/usr/lib/python3/dist-packages/mcomix/__main__.py
--- ./usr/lib/python3/dist-packages/mcomix/__main__.py  2024-07-18 
10:10:55.0 +0900
+++ /usr/lib/python3/dist-packages/mcomix/__main__.py   2025-06-04 
22:42:17.434620562 +0900
@@ -22,7 +22,10 @@

 def main() -> None:
 mp.freeze_support()
-mp.set_start_method('spawn')
+try:
+mp.set_start_method('spawn')
+except RuntimeError:
+pass
 run()



-- System Information:
Debian Release: 13.0
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.12.30-amd64 (SMP w/8 CPU threads; PREEMPT)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=ja_JP.UTf-8, LC_CTYPE=ja_JP.UTf-8 (charmap=UTF-8) (ignored: 
LC_ALL set to ja_JP.UTF-8), LANGUAGE not set

Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages mcomix depends on:
ii  gir1.2-gtk-3.03.24.49-3
ii  python3   3.13.3-1
ii  python3-cairo 1.27.0-2
ii  python3-gi3.50.0-4+b1
ii  python3-gi-cairo  3.50.0-4+b1
ii  python3-pil   11.1.0-5+b1

Versions of packages mcomix recommends:
ii  python3-chardet  5.2.0+dfsg-2

Versions of packages mcomix suggests:
ii  7zip 24.09+dfsg-8
pn  lhasa
ii  mupdf-tools  1.25.1+ds1-6
ii  unrar1:7.1.6-1
ii  unzip6.0-29

-- no debconf information

--
KenichiroMATOHARA
http://matoken.org/
.O.
..O
OOO


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