Make Cask CI generate correctly for partial arch dependencies

[SMillerDev]

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[SMillerDev]

Partially split from: #20334

[Copilot]

Pull request overview

This pull request enhances Cask CI matrix generation to correctly handle partial architecture dependencies, particularly when casks have OS-specific architecture requirements (e.g., requiring x86_64 on macOS but arm64 on Linux). The changes introduce per-OS architecture filtering to ensure CI runners are properly selected based on platform-specific constraints.

Key Changes

• Modified the architectures method to accept an os parameter, enabling OS-specific architecture filtering based on simulated system environments
• Updated filter_runners to separately filter macOS and Linux runners based on their respective architecture requirements
• Added contains_os_specific_artifacts? method to detect casks with platform-specific artifacts that affect OS compatibility
• Introduced comprehensive test coverage for various combinations of OS and architecture dependencies

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 6 comments.

File	Description
Library/Homebrew/dev-cmd/generate-cask-ci-matrix.rb	Enhanced architecture filtering to support OS-specific dependencies; modified filter_runners and architectures methods to handle per-OS architecture constraints
Library/Homebrew/cask/cask.rb	Added contains_os_specific_artifacts? method to improve Linux support detection by checking for OS-specific artifact constraints
Library/Homebrew/cask/artifact.rb	Added LINUX_ONLY_ARTIFACTS constant (empty placeholder for future Linux-specific artifacts)
Library/Homebrew/test/dev-cmd/generate-cask-ci-matrix_spec.rb	Added comprehensive test cases covering various scenarios including mixed OS/arch dependencies, OS-specific dependencies, and system-wide constraints

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[MikeMcQuaid]

Thanks! A few small comments.

[Copilot]

@SMillerDev I've opened a new pull request, #21432, to work on those changes. Once the pull request is ready, I'll request review from you.

[SMillerDev]

No idea why this issue happens here and not on my local install:

Error: Homebrew::DevCmd::GenerateCaskCiMatrix::filter_runners when cask does not have on_system blocks/calls or `depends_on arch` returns an array including everything

Failure/Error:
  expect(generate_matrix.send(:filter_runners, c_app_only_macos))
    .to eq({
      { arch: :arm, name: "macos-14", symbol: :sonoma }          => 0.0,
      { arch: :arm, name: "macos-15", symbol: :sequoia }         => 0.0,
      { arch: :arm, name: "macos-26", symbol: :tahoe }           => 1.0,
      { arch: :arm, name: "ubuntu-22.04-arm", symbol: :linux }   => 1.0,
      { arch: :intel, name: "macos-15-intel", symbol: :sequoia } => 1.0,
      { arch: :intel, name: "ubuntu-22.04", symbol: :linux }     => 1.0,
    })

[bevanjkay]

I can reproduce it using brew tests --only dev-cmd/generate-cask-ci-matrix:161 --generic.

Did a bit of discovery with help from Claude. It looks like when the supports_linux? value on cask is set, the value gets reset during the process, because the SimulateSystem value when running the test with --generic is nil.

The fix below seems to get this working for me, but there may be a better approach. It stores the value before calling contains_os_specific_artifacts? which is the root cause of the reset because it calls refresh.

diff --git a/Library/Homebrew/cask/cask.rb b/Library/Homebrew/cask/cask.rb
index 55de9a0613..f2fe086ddd 100644
--- a/Library/Homebrew/cask/cask.rb
+++ b/Library/Homebrew/cask/cask.rb
@@ -167,9 +167,14 @@ module Cask
     sig { returns(T::Boolean) }
     def supports_linux?
       return true if font?
+
+      # Cache the os value before contains_os_specific_artifacts? refreshes the cask
+      # (the refresh clears @dsl.os in generic/non-OS-specific contexts)
+      os_value = @dsl.os
+
       return false if contains_os_specific_artifacts?
 
-      @dsl.os.present?
+      os_value.present?
     end
 
     sig { returns(T::Boolean) }

[MikeMcQuaid]

thanks, looks fine bar weird tests.