[Bug] Cannot install extensions via GUI in Windows

[WinfredHuang]

Describe the bug

GUI freeze, with error message in the console:

UnicodeDecodeError:
'gbk' codec can't decode byte 0x93 in position 19048:
illegal multibyte sequence
decoding with 'cp936' codec failed

To reproduce

Launch GRASS GUI and install extension via menu.

System description

GRASS version: 8.4.2
Code revision: exported
Build date: 2025-12-03
Build platform: x86_64-w64-mingw32
GDAL: 3.12.0
PROJ: 9.7.0
GEOS: 3.13.1
SQLite: 3.50.4
Python: 3.12.12
wxPython: 4.2.2
Platform: Windows-11-10.0.26200-SP0 (OSGeo4W)

Additional context

This should be reproduced in a Simplified Chinese OS. I know it's an issue about Python encoding.

[saket0187]

Yes, Most probably it's an encoding issue in scripts/g.extension/g.extension.py where operations lack explicit encoding='utf-8'. I'd like to work on this if it can be assigned to me.

[echoix]

What else above is written when it happens. I suspect some files we write by the C-side of grass aren’t written in utf-8. But we are probably reading as utf-8, which is the direction Python is going

[WinfredHuang]

That's exactly what I suspect. Better check other codes for this. Besides, I need a workaround.