CoastalApp will be deprecated. Please switch to https://github.com/oceanmodeling/ufs-coastal . CoastalApp is a NUOPC application implemented following UFS best practices to couple coastal ocean models and other domains (Sea Ice, Atmosphere, Wave, Inland Hydrology, ...)
On arm-darwin/conda with gfortran-clang-mpich toolchain, PAHM erroneously complains about a compiler mismatch.
But in fact, /opt/conda/envs/schism/bin/nf-config was built with the above diagnosed compilers.