Bug: bundled python killed on macOS arm64 (1.4.1+), siril/venv silently removed

Siril version: 1.4.1 to 1.4.4

Operating System: macOS Tahoe 26.3

Package: siril-1.4.4-arm64-2.dmg

Description of the bug

When launched from the command line, Siril 1.4.4 starts but complains with "Python version check failed". Siril 1.4.1 also fails but with a better error message :

Failed to create virtual environment: Child process killed by signal 9

Failed to initialize Python virtual environment: Child process killed by signal 9

The root cause is that Siril 1.4.1 has added a launch constraint on the bundled python

/Applications/Siril.app/Contents/Frameworks/Python.framework/Versions/3.12/bin/python3.12

The launch constraint fails, even when python3.12 is launched by Siril.

This has a very bad consequence when upgrading Siril from a previous version : the directory ~/Library/Application Support/org.siril.Siril/siril/venv is silently removed, without any prompt for confirmation. All modules installed under venv are gone. This happened to me and is the reason I send this bug report. I prefer starting all my processes from the command line, in particular to log stdout and stderr.

I suggest two independent fixes :

  1. remove the launch constraint which serves no useful purpose

  2. never remove silently a complete directory, always prompt the user before

Reproduction

Reproduction steps: Run in a Terminal window

/Applications/Siril.app/Contents/MacOS/siril >& logfile &

Expected result: the directory ~/Library/Application Support/org.siril.Siril/siril/venv is created for a fresh install, and preserved for an upgrade.

Actual result: the directory ~/Library/Application Support/org.siril.Siril/siril/venv is not created for a fresh install, and is silently removed for an upgrade. The option "Reset python venv" also fails.

Additional information

$ sudo log show --last 2m --predicate 'eventMessage contains "python"' | tail -20

Timestamp Thread Type Activity PID TTL
2026-06-25 18:28:38.517907+0200 0x3b8afb4 Default 0x0 0 0 kernel: (AppleMobileFileIntegrity) AMFI: Launch Constraint Violation (enforcing), error info: c[4]p[3]m[1]e[0], (Constraint not matched) launching proc[vc: 6 pid: 86008]: /Applications/Siril.app/Contents/Frameworks/Python.framework/Versions/3.12/bin/python3.12, launch type 0, failure proc [vc: 1 pid: 1446]: /System/Applications/Utilities/Terminal.app/Contents/MacOS/Terminal

2026-06-25 18:28:38.517969+0200 0x3b8afb5 Default 0x0 0 0 kernel: (AppleSystemPolicy) ASP: Security policy would not allow process: 86008, /Applications/Siril.app/Contents/Frameworks/Python.framework/Versions/3.12/bin/python3.12

Workaround : start Siril by double clicking on /Applications/Siril.app in Finder. Please do not rely on the existence of this workaround to ignore the silent removal of siril/venv. After this directory is gone, it is too late to recover it with the workaround. The workaround recreates a minimal venv but the original installed modules are not recovered.