gfortran installation not found

[t-kalinowski]

Setting up a new Mac, I ran

rig sysreqs add gfortran

producing output:

[INFO] Running `sudo` for installing gfortran. This might need your password.
Password:
[INFO] Downloading https://github.com/R-macos/gcc-darwin-arm64/releases/download/R-4.2.0-release/gfortran-12.0.1-20220312-is-darwin20-arm64.tar.xz -> /tmp/rig/gfortran-12.0.1-20220312-is-darwin20-arm64.tar.xz
[INFO] Unpacking gfortran
[INFO] Updating gfortran link to your Apple SDK
[INFO] > Updating gfortran SDK path to /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk

Then, attempting to install a package with fortran code:

==> R CMD INSTALL --preclean --no-multiarch --with-keep.source quickr.test.pkg

* installing to library ‘/Users/tomasz/Library/R/arm64/4.4/library’
* installing *source* package ‘quickr.test.pkg’ ...
** using staged installation
** libs
clang -arch arm64 -I"/Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/include" -DNDEBUG   -I/opt/R/arm64/include    -fPIC  -falign-functions=64 -Wall -g -O2  -march=native -mtune=native -c quick_add_ab_bridge.c -o quick_add_ab_bridge.o
/opt/gfortran/bin/gfortran -arch arm64  -fPIC  -Wall -g -O2  -march=native -mtune=native -c  quick_add_ab_fsub.f90 -o quick_add_ab_fsub.o
using C compiler: ‘Apple clang version 16.0.0 (clang-1600.0.26.6)’
sh: /opt/gfortran/bin/gfortran: No such file or directory
using SDK: ‘MacOSX15.2.sdk’
make: /opt/gfortran/bin/gfortran: No such file or directory
make: *** [quick_add_ab_fsub.o] Error 1
ERROR: compilation failed for package ‘quickr.test.pkg’
* removing ‘/Users/tomasz/Library/R/arm64/4.4/library/quickr.test.pkg’

Exited with status 1.

It seems that the gfortran that rig installs is not automatically found by the R that rig installes.

The solution was relatively simple: install the gfortran package linked to from https://mac.r-project.org/tools (link)