workflows: install svn when brew fetch needs it

[Moisan]

• Have you followed the guidelines for contributing?
• Have you ensured that your commits follow the commit style guide?
• Have you checked that there aren't other open pull requests for the same formula update/change?
• Have you built your formula locally with HOMEBREW_NO_INSTALL_FROM_API=1 brew install --build-from-source <formula>, where <formula> is the name of the formula you're submitting?
• Is your test running fine brew test <formula>, where <formula> is the name of the formula you're submitting?
• Does your build pass brew audit --strict <formula> (after doing HOMEBREW_NO_INSTALL_FROM_API=1 brew install --build-from-source <formula>)? If this is a new formula, does it pass brew audit --new <formula>?

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The scheduled.yml workflow is failing on acme and lcs continuously (see #139929) because brew fetch -s needs svn to be installed if the source url is a svn repository.

Note that I'm relatively new to Github actions, I couldn't figure out how to test this change properly.

[carlocab]

I think we should handle this more like the way we handle Homebrew curl instead of trying to parse the output of brew fetch.

[Moisan]

We would need something like using: :svn to be required on svn url fields in formulae. brew fetch --json=v2 doesn't include any mention of svn currently for formulae like acme and lcs (except svn being in their URL). But I agree that would be much cleaner.

[carlocab]

You could probably check if svn is a :build dependency. That may have some false positives, but as long as there are no false negatives (and there aren't too many false positives, and there shouldn't be), that seems fine.

[ZhongRuoyu]

$ brew ruby -e 'puts Formula[ARGV.first].deps.any? { |d| d.name == "subversion" && d.implicit? }' acme
true
$ brew ruby -e 'puts Formula[ARGV.first].deps.any? { |d| d.name == "subversion" && d.implicit? }' hello
false

Maybe?

[Moisan]

brew deps --include-build --direct could also work but it might lead to more false positive than @ZhongRuoyu approach.

[carlocab]

Looks good to me!

[MikeMcQuaid]

Seems fine for now, would be nice to make this an actual Homebrew command rather than relying on internals here.

[carlocab]

Seems fine for now, would be nice to make this an actual Homebrew command rather than relying on internals here.

Yes, there's enough non-trivial logic in here that making it a proper brew command makes sense at this point.