linkage_checker: allow cyan extras

[devnoname120]

This is necessary because cyan injects in an IPA some frameworks that link to iOS system frameworks. These system frameworks are not on macOS but they are not needed because the IPA is to be sideloaded on an iPhone, these frameworks will never be used on macOS itself.

This is required to fix Homebrew/homebrew-core#271929 CI.

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[Copilot]

Pull request overview

Updates Homebrew’s linkage checker allowlist to accommodate cyan’s bundled IPA “extras” that reference iOS-only system frameworks (not present on macOS), preventing false-positive broken-linkage failures in CI.

Changes:

• Refactors broken_dylibs_allowed? to gate by formula name via a case.
• Adds a cyan-specific path matcher to allow broken dylibs under site-packages/cyan/extras/.

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[MikeMcQuaid]

Thanks!

Could these dylibs be either 1) stripped or 2) moved to a location that the linkage checker doesn't look (can't remember if this is a thing or not, excuse me if it isn't) instead?

[devnoname120]

@MikeMcQuaid Unfortunately no…

1. The checker reads Mach-O load commands. Stripping the frameworks would just remove symbols/debug info, not linkage entries, so the missing iOS framework refs would still be reported.

Code ref:

brew/Library/Homebrew/os/mac/mach.rb

Line 107 in 4d4adf0

lcs = macho.dylib_load_commands

2. The checker walks through the whole keg so there is no path where I could sneak the frameworks so that it wouldn’t look at them.

The checker logic for ignoring things:

brew/Library/Homebrew/linkage_checker.rb

Lines 145 to 160 in 4d4adf0

	@keg.find do |file|
	next if file.symlink? || file.directory?
	file = begin
	BinaryPathname.wrap(file)
	rescue NotImplementedError
	next
	end
	next if !file.dylib? && !file.binary_executable? && !file.mach_o_bundle?
	next unless file.arch_compatible?(Hardware::CPU.arch)
	# weakly loaded dylibs may not actually exist on disk, so skip them
	# when checking for broken linkage
	keg_files_dylibs[file] =
	file.dynamically_linked_libraries(except: :DYLIB_USE_WEAK_LINK)

[MikeMcQuaid]

Thanks!

[devnoname120]

@MikeMcQuaid Thank you!