pygobject / glib: missing typelib bindings for cairo package?

[jayaddison]

Output of brew config

HOMEBREW_VERSION: 4.4.26
ORIGIN: https://github.com/Homebrew/brew
HEAD: f1041842141f20bc701b522d4371d7843d905580
Last commit: 4 days ago
Branch: stable
Core tap HEAD: 7a6d3a8f14e8d4056674c0114e0e684a922e5259
Core tap last commit: 3 hours ago
Core tap JSON: 28 Mar 11:28 UTC
Core cask tap HEAD: e63c284f0af664e0be7e7bbf386428b703958626
Core cask tap last commit: 26 minutes ago
Core cask tap JSON: 28 Mar 11:28 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: ["--no-quarantine"]
HOMEBREW_COLOR: set
HOMEBREW_MAKE_JOBS: 3
HOMEBREW_NO_AUTO_UPDATE: set
HOMEBREW_NO_INSTALL_CLEANUP: set
Homebrew Ruby: 3.3.7 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.3.7/bin/ruby
CPU: 3-core 64-bit dunno
Clang: 15.0.0 build 1500
Git: 2.49.0 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 14.7.4-arm64
CLT: 16.2.0.0.1.1733547573
Xcode: 15.4 => /Applications/Xcode_15.4.app/Contents/Developer
Rosetta 2: false

Output of brew doctor

Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!
Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  openssl@1.1

Warning: The following formulae have the same name as core formulae:
  aws/tap/eksctl
  hashicorp/tap/consul-template
  hashicorp/tap/levant
  hashicorp/tap/nomad
  hashicorp/tap/packer
  hashicorp/tap/terraform
  hashicorp/tap/terraform-ls
  hashicorp/tap/vault
  hashicorp/tap/waypoint
Some of these can be resolved with:
  brew untap aws/tap

Warning: You have an unnecessary local Cask tap.
This can cause problems installing up-to-date casks.
Please remove it by running:
  brew untap homebrew/cask

Warning: You have an unnecessary local Core tap!
This can cause problems installing up-to-date formulae.
Please remove it by running:
 brew untap homebrew/core

Description of issue

Context

Versions v3.51.1 onwards of pygobject require girepository-2.0 as a dependency:

• https://gitlab.gnome.org/GNOME/pygobject/-/blob/e3dee9719e7249acfa7e78a3bbae251301a134a4/NEWS#L9-10
• https://docs.gtk.org/girepository/migrating-gi.html
• https://gitlab.gnome.org/GNOME/pygobject/-/merge_requests/320

This caused some problems for the MacOS GitHub Actions CI unit tests for matplotlib, because the GLib-2.0 dependency couldn't be found; I reported that at: matplotlib/matplotlib#29732

As a workaround, matplotlib currently has an upper-bound version pin on pygobject: matplotlib/matplotlib#29734

Issue

I'm now trying to remove the version pin to unblock pygobject updates, but have encountered a problem with discovery of cairo typelib bindings:

Successfully installed PyGObject-3.52.3 cairocffi-1.7.1 cffi-1.17.1 pycairo-1.27.0 pycparser-2.22
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/gi/importer.py", line 139, in create_module
    introspection_module = get_introspection_module(namespace)
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/gi/module.py", line 243, in get_introspection_module
    module = IntrospectionModule(namespace, version)
  File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/gi/module.py", line 111, in __init__
    repository.require(namespace, version)
    ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
gi.RepositoryError: Typelib file for namespace 'cairo', version '1.0' not found

I've attempted to add an explicit brew reinstall cairo in the hope that this might (re)install and regenerate typelib bindings -- but they remain unavailable.

Can anyone help me figure out how to ensure that the required cairo typelib files are available? Thank you in advance!

NB: I'll provide the relevant brew config and brew doctor output shortly.

Edit: update to provide brew config and brew doctor output

[jayaddison]

Two questions from browsing the glib formula:

• The formula explicitly deactivates cairo support in gobject-introspection at build-time. Could that explain the absence of a cairo typelib file?

  • Initial thoughts: ...sure, maybe it could be an explanation? There is a bug from March of Y2011 in the GNOME Bugzilla that indicates that a very-similar looking error (failure to find/load a cairo binding) was resolved within gobject-introspection: https://bugzilla.gnome.org/show_bug.cgi?id=645692

• The formula references a number of girepository-1.0 directories -- do those continue to be relevant for the .typelib search path when using glib-2.0?

  • Initial thoughts: I'm not sure yet. Neither the migration guide nor the gi.Repository documentation seem to mention any required adjustments and/or alternatives to the typelib library search paths.

[jayaddison]

The formula explicitly deactivates cairo support in gobject-introspection at build-time. Could that explain the absence of a cairo typelib file?

• Initial thoughts: ...sure, maybe it could be an explanation? There is a bug from March of Y2011 in the GNOME Bugzilla that indicates that a very-similar looking error (failure to find/load a cairo binding) was resolved within gobject-introspection: https://bugzilla.gnome.org/show_bug.cgi?id=645692

It now seems more likely to me that this is intentional, due to a cyclic dependency beween cairo and gobject-introspection: https://gitlab.freedesktop.org/cairo/cairo/-/issues/141

Also, I found a thread on the pycairo bugtracker mentioning to brew install cairo before installing pycairo from PyPI (as matplotlib is doing currently): pygobject/pycairo#89

...so I'll leave that change in my branch for now (despite the comment probably being incorrect; I'll fix that if+when the PR reaches readiness).

[cho-m]

Bindings are provided by gobject-introspection not glib nor cairo:

❯ readlink $(brew --prefix)/lib/girepository-1.0/cairo-1.0.typelib
../../Cellar/gobject-introspection/1.82.0/lib/girepository-1.0/cairo-1.0.typelib

[jayaddison]

Thank you, @cho-m - I'll give that a try in a few moments.

[jayaddison]

This may take me a while longer to confirm @cho-m - there is a separate error (a .dylib loading failure), that I believe occurs before the Cairo typelib file loading attempt, both when I either substitute or supplement glib with gobject-introspection.

That's the same error that I originally reported and worked-around by version-pinning PyGObject in matplotlib.

[carlocab]

It might help to try using Homebrew python@3.13. I suspect your library loading failure will go away using that.

You may need to avoid using Homebrew Python for other reasons, but it would be good to know if using it fixes your error to help you figure out what you might need to do with your preferred Python distribution.

[jayaddison]

Thanks @carlocab - I'll experiment with using Homebrew Python, likely early next week, to determine whether that affects the dynamic library loading.

[jayaddison]

I haven't yet gotten around to doing that testing; I hope to soon, but I'm not certain exactly when it will be.