Caches for `macos-15-intel` and `macOS-latest` collide

[Bisaloo]

When trying to run checks on both Intel and Apple Silicon macOS, I get errors because packages are not compiled on the correct architecture.

This seems to come from the fact that a single cache named macOS Sequoia 15.7.2-R version 4.6.0 (ge:17; iid:2fdf6c18-697a-4ba7-b8ef-11c0d92f1327)-1-82bdd66141639e34448b2ca5cf0fc62c31a89eed9ec9a0fdd6754d4a329dbffc is created and used in both workflows.

Indeed, there doesn't seem to be anything that differentiate these two runners in the cache key defined by r-lib/actions/setup-r-dependencies:

actions/setup-r-dependencies/action.yaml

Line 204 in 6f6e5bc

key: ${{ format('{0}-{1}-{2}-{3}', steps.install.outputs.os-version, steps.install.outputs.r-version, inputs.cache-version, hashFiles(format('{0}/.github/pkg.lock', inputs.working-directory ))) }}

Would it be possible to let users add a custom extra value to include in the key for example?

[Bisaloo]

Thinking about this again:

Would it be possible to let users add a custom extra value to include in the key for example?

cache-version is basically this. So I added it to my job matrix and set cache-version: 1 for the intel mac runner, and cache-version: 2 for the apple silicon one.

I'll leave this up to you if you think it should be handled by default by r-lib/actions or is the described workaround is good enough for the relatively rare cases where users add the intel runner to their job matrix.