No longer works on macOS

[Saviq]

Bug Description

Expects the debian module to be there, so fails on macOS.

To Reproduce

Try this Homebrew recipe:

Homebrew/homebrew-core@master...Saviq:homebrew-core:snapcraft-8-5

part yaml

N/A

Relevant log output

$ snapcraft --version
Traceback (most recent call last):
  File "/opt/homebrew/bin/snapcraft", line 5, in <module>
    from snapcraft.application import main
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/snapcraft/application.py", line 38, in <module>
    from snapcraft import cli, commands, errors, models, services, store
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/snapcraft/cli.py", line 34, in <module>
    from snapcraft.parts import plugins
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/snapcraft/parts/__init__.py", line 21, in <module>
    from .lifecycle import patch_elf, set_global_environment, set_step_environment
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/snapcraft/parts/lifecycle.py", line 40, in <module>
    from .parts import PartsLifecycle, launch_shell
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/snapcraft/parts/parts.py", line 25, in <module>
    from craft_archives import repo
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/craft_archives/repo/__init__.py", line 19, in <module>
    from .installer import install, install_in_root
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/craft_archives/repo/installer.py", line 25, in <module>
    from .apt_sources_manager import AptSourcesManager
  File "/opt/homebrew/Cellar/snapcraft/8.5.0/libexec/lib/python3.13/site-packages/craft_archives/repo/apt_sources_manager.py", line 27, in <module>
    from debian.deb822 import Deb822
ModuleNotFoundError: No module named 'debian'

[tigarmo]

That's odd - craft-archives uses the python-debian package which is a regular PyPI package, so it should be present on the environment. Does the issue happen if you install craft-archives on a venv and do from craft_archives import repo?

[Saviq]

@tigarmo is there a point in having python-debian on macOS? So far it was only included on the linux side of the brew formula:

https://github.com/Saviq/homebrew-core/blob/dea4f2af75ade15db4abb0bfa2dcdd6110c88a00/Formula/s/snapcraft.rb#L73-L76

(there are some others, too, so there must be prior art around skipping these where appropriate)

[tigarmo]

arguably there's no point in having craft-archives at all on macOS, but the library itself doesn't have any checks

[Saviq]

If Snapcraft can/should deal without craft-archives, that's even better - please transfer the issue to Snapcraft in that case.

[tigarmo]

It's still unclear to me whether there is an issue at all. Snapcraft declares that it needs craft-archives, which in turn declares that it needs python-debian. Any setup that doesn't include the dependencies is bound to be, at the very least, fragile.

Wouldn't the correct fix be to add python-debian to the homebrew formula?

[Saviq]

Not my call to make, but I'd say if we can, we shouldn't have dormant bytes in there. There's a reason why the formula has on_linux do….