The R-CMD-check action in the oce
package (https://github.com/dankelley/oce/blob/develop/.github/workflows/R-CMD-check.yaml) works for windows and two ubuntu tests, but not for macos. The problem is that gfortran is not found (https://github.com/dankelley/oce/runs/1750511218?check_suite_focus=true).
The package builds fine locally (on macos) and using the rhub macos method, so I'm not actually worried about the code, but rather about the action.
I suspect this problem will arise with any R package that includes Fortran code, and so I wonder if there is a general solution that can help others in the same boat.