Extensions cannot run because Flatpak ships Python 3.12 while community extensions target Python 3.10/3.11

[Raian256]

Summary

Community‑maintained extensions for Sioyek (e.g. the official add_text.py, translate.py, etc.) assume they will be executed with the system Python 3.10/3.11.
The Flatpak build, however, bundles Python 3.12 inside the sandbox and does not expose the host interpreter. This mismatch means:

• python3 -m sioyek.add_text … inside the Flatpak fails with

  ModuleNotFoundError: No module named 'sioyek'
  

  because the extension was installed under ~/.local/lib/python3.10/site‑packages, not python3.12/site‑packages.

• Attempting to pip install sioyek for 3.12 inside the sandbox is impossible:

  • Flatpak is immutable (no pip / no build tools).
  • Even if I expose my host site‑packages, byte‑compiled .so wheels built for 3.10 won’t load under 3.12.

• Work‑arounds tried:

  1. Expose host site‑packages → version mismatch (3.10 vs 3.12).
  2. Wrap host python in ~/bin/python3-host + flatpak override --filesystem=~/bin:ro → spawning from outside the sandbox is counterproductive.
  3. flatpak-spawn --host same as above.

Running outside the sandbox doesn't seem to work because the extensions for some reason need access to the path of the instance that is running, "%{sioyek_path}".

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Steps to reproduce

1. Install Sioyek via Flatpak on Pop !_OS 22.04.

2. Clone the official extensions repo
   git clone https://github.com/ahrm/sioyek-python-extensions.git ~/.sioyek-extensions

3. Add in prefs_user.config:

   new_command _add_text python -m sioyek.add_text "%{sioyek_path}" "%{local_database}" "%{shared_database}" "%{file_path}" "%{selected_rect}" "%{command_text}"

4. pip3.10 install --user --upgrade ~/.sioyek-extensions

5. Add this env var to the flatpak and allow the sandbox to read from it PYTHONPATH=/home/user/.local/lib/python3.10/site-packages

6. Restart Sioyek, invoke _add_text.
   Actual result

/usr/bin/python3: Error while finding module specification for 'sioyek.add_text'
(ModuleNotFoundError: No module named 'sioyek')

Root causeIt doesn't find the module even tho it is in the PYTHONPATH because it is checking python3.12/site-packages

Why this matters

• All official/community extensions depend on being able to import the sioyek Python package.
• Users cannot feasibly rebuild wheels for Python 3.12 inside the immutable sandbox.

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Possible solutions

1. Bundle Python 3.10/3.11 (same minor version the upstream dev used) inside the Flatpak, or
2. Ship the extensions as part of the Flatpak and ensure they import against the bundled runtime.

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Environment

• OS: Pop !_OS 22.04 (Ubuntu 22.04 base)
• Host Python: 3.10/12
• Flatpak Sioyek runtime Python: 3.12.0
• Sioyek Flatpak version: 2.0.0.fl1
• Extensions repo commit: ee86154

Thanks in advance for your time and attention.