No "available interpreter-os association" is visible on the action?

[stdedos]

i.e. on https://github.com/ruby/setup-ruby/blob/f321cf5a4d1533575411f8752cf25b86478b0442/ruby-builder-versions.json I don't see which interpreter is available on which OS.

e.g. even though truffleruby+graalvm-21 supposedly exists, it does not work in my action (https://github.com/stdedos/interception/actions/runs/11123894333/job/30908313355)

• Should you create a matrix? (ie like How to find available versions? actions/setup-python#15 (comment))
• (For both repositories), should that be (a) automatically done, and (b) give some "permalink-like" url to "that matrix"?

[eregon]

In general it's every version is available on all platforms on which it can be built.
The full list is at https://github.com/ruby/ruby-builder/releases/tag/toolcache FWIW.
There are some known version-platform combinations which do not work:

setup-ruby/index.js

Lines 173 to 195 in c04af2b

	// Well known version-platform combinations which do not work:
	if (engine === 'ruby' && platform.startsWith('macos') && os.arch() === 'arm64' && common.floatVersion(version) < 2.6) {
	throw new Error(`CRuby < 2.6 does not support macos-arm64.
	Either use a newer Ruby version or use a macOS image running on amd64, e.g., macos-13 or macos-12.
	Note that GitHub changed the meaning of macos-latest from macos-12 (amd64) to macos-14 (arm64):
	https://github.blog/changelog/2024-04-01-macos-14-sonoma-is-generally-available-and-the-latest-macos-runner-image/
	If you are using a matrix of Ruby versions, a good solution is to run only < 2.6 on amd64, like so:
	matrix:
	ruby: ['2.4', '2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3']
	os: [ ubuntu-latest, macos-latest ]
	# CRuby < 2.6 does not support macos-arm64, so test those on amd64 instead
	exclude:
	- { os: macos-latest, ruby: '2.4' }
	- { os: macos-latest, ruby: '2.5' }
	include:
	- { os: macos-13, ruby: '2.4' }
	- { os: macos-13, ruby: '2.5' }
	But of course you should consider dropping support for these long-EOL Rubies, which cannot even be built on recent macOS machines.`)
	} else if (engine === 'truffleruby' && platform.startsWith('windows')) {
	throw new Error('TruffleRuby does not currently support Windows.')
	}

Regarding truffleruby+graalvm-21 that's just really old and I didn't build it on newer runners.
I would suggest to only test the latest release of truffleruby (with just ruby-version: truffleruby).
truffleruby+graalvm is basically redundant in CI (unless you need interop with Java or other languages).

Maintaining a matrix would be too high overhead.

[stdedos]

The full list is at ruby/ruby-builder@toolcache (release) FWIW.

That is amazing already 😁

Would you consider mentioning it here?

setup-ruby/README.md

Lines 39 to 57 in c04af2b

	### Supported Platforms
	The action works on these [GitHub-hosted runners](https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners#supported-runners-and-hardware-resources) images. Runner images not listed below are not supported yet. `$OS-latest` just alias to one of these images.
	| Operating System | Supported |
	| ---------------- | --------- |
	| Ubuntu | `ubuntu-20.04`, `ubuntu-22.04`, `ubuntu-24.04` |
	| macOS | `macos-12`, `macos-13`, `macos-14` |
	| Windows | `windows-2019`, `windows-2022` |
	The prebuilt releases are generated by [ruby-builder](https://github.com/ruby/ruby-builder)
	and on Windows by [RubyInstaller2](https://github.com/oneclick/rubyinstaller2).
	The `mingw`, `ucrt` and `mswin` builds are generated by [ruby-loco](https://github.com/MSP-Greg/ruby-loco).
	`ruby-head` is generated by [ruby-dev-builder](https://github.com/ruby/ruby-dev-builder),
	`jruby-head` is generated by [jruby-dev-builder](https://github.com/ruby/jruby-dev-builder),
	`truffleruby-head` is generated by [truffleruby-dev-builder](https://github.com/ruby/truffleruby-dev-builder)
	and `truffleruby+graalvm` is generated by [graalvm-ce-dev-builds](https://github.com/graalvm/graalvm-ce-dev-builds).
	The full list of available Ruby versions can be seen in [ruby-builder-versions.json](ruby-builder-versions.json)
	for Ubuntu and macOS and in [windows-versions.json](windows-versions.json) for Windows.

The combinations of the available versions and runners can be seen here: https://github.com/ruby/ruby-builder/releases/tag/toolcache

(tl;dr that's what I'm asking here)

[eregon]

Ah yes, sure, PR welcome