GHA recently bumped macos-latest to the arm64 based runners. Therefore we can no longer use R versions below 4.2 on these runners because these versions are not available on arm64.

CI that is using a configuration like {os: macos-latest, r: '4.0'} now fails like so.

#setup-r
Error: Error: Failed to resolve R version 3.6 at https://api.r-hub.io/rversions/resolve/3.6/mac/arm64.

Perhaps this problem can be caught earlier to explicitly disable R < 4.1 on macos-arm64, explainining that macos-latest now requires R 4.2 or newer.

Alternatively print the error message that is in https://api.r-hub.io/rversions/resolve/3.6/mac/arm64 .