Run tests on AArch64 in CI

[frewsxcv]

Uses run-on-arch-action to run tests in CI on a virtualized AArch64 environment. This slows down CI quite a bit, but if it were up to me I'd say it's worth the trade-off, since this could surface some critical issues on a soon-to-be tier 1 platform. Hopefully GitHub will release native integration with AArch64 in the future such that this slowness is temporary.

[emilio]

I have some questions, but this is great!

[emilio]

Can we somehow not duplicate all the testing setup? If not, can we document why?

For example, the curl command to install rust seems like it should work with actions-rs/toolchain instead. If it doesn't, why not?

[frewsxcv]

The way run-on-arch-action works is by creating a container and the current directory is mounted as a volume within the container. If I installed Rust with actions-rs/toolchain, the binaries would not be copied into the container. Does that answer your question?

[saleemrashid]

Instead of using run-on-arch-action, wouldn't it be possible to install the binfmt-support and qemu-user-static packages and then just run the tests as usual but for the AArch64 target (and they'll transparently execute under QEMU because of binfmt-support)

Edit: On second thoughts, you might need the dynamic linker and libraries; which is what either the container or the multiarch packages are for. You could still build outside the container.

[emilio]

Looks fine to me, mind squashing? Specially the test / empty commits. Other than that it looks good, thank you,

[frewsxcv]

Looks fine to me, mind squashing? Specially the test / empty commits. Other than that it looks good, thank you,

Squashed!

Instead of using run-on-arch-action, wouldn't it be possible to install the binfmt-support and qemu-user-static packages and then just run the tests as usual but for the AArch64 target (and they'll transparently execute under QEMU because of binfmt-support)

Edit: On second thoughts, you might need the dynamic linker and libraries; which is what either the container or the multiarch packages are for. You could still build outside the container.

This would be an improvement! But I've already spent longer than I planned to on this pull request, so I'm going to leave that for someone else.

[emilio]

Looks sensible, thank you!