True.

Should this come in the form of an env. variable? Or an input? Or how are you executing this in self-hosted runners?

Hm... RUNNER_ARCH... that should do it, at least for some cases (I'm not sure all our bundled software supports ARM, but I can create a big enough test to validate it and then make sure we incorporate this, somehow). Thanks for your feedback.

Hm... I'm not yet sure how I can test this, actually, unless the online runners (not self-hosted) also support that env. element. If not, it'll have to be by trial-and-error, I guess, maybe with your help.

I started looking into this and it seems that for all the use cases we've considered, the only one where fetching stuff for ARM would be possible is Gleam (and even then only Mac and Linux, no Windows). We fetch our Erlang/OTP builds from Hex, as well as our Elixir builds, and none of them seem to be available for ARM. Maybe @ericmj can further elaborate or even correct me.

Elixir and Rebar are architecture agnostic.

Bob only builds Erlang for x86/x64. We could provide ARM builds also (we do this for docker images already) but the current build scripts assume x86 so they would need to be modified for any changes ARM requires.

https://github.com/hexpm/bob/blob/main/lib/bob/job/otp_checker.ex
https://github.com/hexpm/bob/tree/main/priv/scripts/otp

@ericmj, would you accept pull requests to have the builds produce for ARM, and maybe then this action could use those? We can leave this issue open, still, but this is not a limitation the action can directly work around, at the moment, given what is explained above.

Yes, we would accept PRs. I have linked the places where I think changes need to be made in my previous comment.

Just hit this same issue with github actions using self hosted. Watching this issue for updates.

I am also interested in support for alpine > ubuntu as well for smaller overall image sizes. (Although I suspect github will also need to support that here: https://github.com/actions/runner-images)

There's potential partial support for this in #278. If that gets approved/merged we should retitle this issue Support Windows/ARM (my limited Windows knowledge indicates it runs in ARM these days, too). This'll actually be linked to the pull request and closed when that one's merged. If in need for "other" ARM support, we'll either open a new issue or reopen this one.

Just in time for the official arm release! https://github.blog/2024-06-03-arm64-on-github-actions-powering-faster-more-efficient-build-systems/