Have Linux CI for casks

[SMillerDev]

Verification

• This issue's title and/or description do not reference a single formula e.g. brew install wget. If they do, open an issue at https://github.com/Homebrew/homebrew-core/issues/new/choose instead.

Provide a detailed description of the proposed feature

Now that linux support is added to casks, we should also set up CI for casks.

What is the motivation for the feature?

With CI, we find bugs before they reach people.

How will the feature be relevant to at least 90% of Homebrew users?

With CI, we find bugs before they reach people.

What alternatives to the feature have been considered?

Removing linux support for casks again?

[MikeMcQuaid]

Now that linux support is added to casks, we should also set up CI for casks.

Homebrew/brew CI or Homebrew/homebrew-cask CI?

I assume the latter (in which case it should probably be in that repo).

I think it would be good to do more manual testing first e.g. try to install all non-conflicting casks on Linux and see what works/breaks. Introducing a 🔴 to most homebrew-cask PRs seems like a 👎🏻.

[SMillerDev]

Homebrew/brew CI or Homebrew/homebrew-cask CI?

I'd say both actually.

I assume the latter (in which case it should probably be in that repo).

I thought about it, but the runner selection logic actually lives here in the repo

I think it would be good to do more manual testing first e.g. try to install all non-conflicting casks on Linux and see what works/breaks. Introducing a 🔴 to most homebrew-cask PRs seems like a 👎🏻.

Cask CI actually only runs on a subset of the supported versions so if no Linux support is declared it won't test on Linux (if we keep the same logic)

[MikeMcQuaid]

I'd say both actually.

We already have Homebrew/brew CI for this, no?

Cask CI actually only runs on a subset of the supported versions so if no Linux support is declared it won't test on Linux (if we keep the same logic)

Ok. I guess my experience so far is that there's more casks supposedly supported on Linux than will actually install on Linux without errors and this needs addressed first.

Alternatively, we go back to the model of explicitly adding some DSL to everything known to actually work on Linux (at least temporarily)

[SMillerDev]

We already have Homebrew/brew CI for this, no?

The tests run on Linux, but things like test cask run on macOS only AFAIK.

[MikeMcQuaid]

The tests run on Linux, but things like test cask run on macOS only AFAIK.

Not sure which job this refers to?

[SMillerDev]

Looks like I mixed a couple of them up. There is "test default formula" on various platforms, but no casks. There is only https://github.com/Homebrew/brew/actions/runs/13862934537/job/38795614991 on macOS for audits

[MikeMcQuaid]

Looks like I mixed a couple of them up. There is "test default formula" on various platforms, but no casks. There is only Homebrew/brew/actions/runs/13862934537/job/38795614991 on macOS for audits

@SMillerDev Once brew test-bot sufficiently supports casks: I think adding a test default cask job would make sense. For that to be useful, though, the Cask CI would have to be mostly moved over to use brew test-bot.