Build macOS executable for M- series Macs

[JakenHerman]

I noticed there was a GitHub Action that generated a Windows (.exe) executable, but nothing for macOS. This pull request adds a GitHub Action to generate an executable binary for macOS.

Testing

There is a test step in the GitHub Action, so no manually testing should be necessary, however, if you'd like you can download the artifact produced from the GitHub Action run. You'll need to run chmod +x weasyprint-macos/dist/weasyprint in order to be able to execute, but once you do, you can run ./weasyprint-macos/dist/weasyprint --info to verify the executable is working.

Use cases

This executable can be bundled with Electron or Tauri applications so PDF generation is a possibility without requiring users of the built applications to install additional resources.

[JakenHerman]

I'm not sure where the appropriate place to update documentation on using this binary would be, but I would be happy to contribute to the documentation as the team sees fit. You can see the result of the GitHub action run on my fork here.

[liZe]

Hi!

Thanks for this pull request.

For now, we’re not sure that we want to generate and support a macOS executable. We tried with Windows, and it actually introduced a number of bugs that are hard to understand, reproduce, and fix for us. The problem is that we don’t have regular Windows or macOS testers in the team, and that nobody wants to take care of this in the long term. So, if we have a large number of users ready to try, report and fix bugs, why not, but we can’t promise anything.

That being said, from a technical point of view, there’s a couple of things I don’t understand:

• Isn’t PyInstaller supposed to find libraries? All the --add-binary should be useless if we do set the DYLD_FALLBACK_LIBRARY_PATH environment variable when calling PyInstaller (see this line:

  WeasyPrint/.github/workflows/tests.yml

  Lines 44 to 45 in db288a4

  	env:
  	DYLD_FALLBACK_LIBRARY_PATH: /opt/homebrew/lib

  ). Even better: if we don’t use setup-python and rely on Homebrew’s Python instead, we shouldn’t need to set the environment variable at all.
• I don’t think that we should set DYLD_LIBRARY_PATH at runtime. PyInstaller should be able to put the libraries somewhere at runtime and to let Python find them automatically, with no runtime hook. That’s at least what it does for Windows, and I think that it was the case for macOS too last time we tried to generate a macOS executable.