Test using macos-15
It looks like we're trying to download an macOS arm64 release, but one isn't available for the pinned nightly.
I poked around a little, and it seems that platform wasn't targeted until earlier this year. https://github.com/nim-lang/nightlies/releases/tag/2025-02-01-version-2-0-1ff69eae17388be06221369b2bb08f8808905472 is an option if we're fine targeting 2.0.15.
Thanks for the PR. I'm not against this, now that Nim recently starting providing arm64 releases for macOS, and after we first merge:
- https://github.com/exercism/nim/pull/625
- https://github.com/exercism/nim/pull/622
However, I'd like to note that this PR is not just a bump of OS version and dependencies; it changes the architectures that we're testing. I might lean slightly towards simply adding arm64 macOS to the testing matrix, rather than replacing x86_64 macOS. I was also going to get around to adding arm64 Linux and Windows.
The current runner labels and their associated runners are documented here. The macOS labels are not particularly intuitive:
- x86_64:
macos-13(AKAmacos-13-large),macos-14-large, andmacos-15-large - arm64:
macos-14(AKAmacos-14-xlarge), andmacos-15(AKAmacos-15-xlarge)
I suppose it was done like that to optimize for cost at the expense of making the upgrades macos-13 -> macos14 or macos-13 -> macos-15 a non-obvious architecture change.
Furthermore, I was not a fan of the fact that people who used macos-latest got switched from x86_64 to arm64 underneath their feet. I'm glad I pin to specific labels everywhere.