Updating compilers on conda-forge should be coordinated with the core team, since this is likely to affect a significant part of the >17k feedstocks part of conda-forge. Best reach out in the compilers channel: conda-forge/conda-forge-compilers - Gitter.
The compilers themselves are more than a single feedstock, they are usually split into actual implementations, activation scripts, compiler wrapper and version pinning (not only affecting the compilers, but the rest of the conda-forge as well). For Linux this are
- implementations: ctng-compilers-feedstock
- activation scripts: ctng-compiler-activation-feedstock
- compiler wrapper: compilers-feedstock
- global pinning: conda-forge-pinning-feedstock
For the OSX toolchain the repos are separate, if you ever need to find a feedstock providing a package, checkout conda-forge feedstocks | community driven packaging for conda. The compiler toolchain for OSX is built-up from clang/clang++ and gfortran without gcc/g++. Starting from the compiler wrapper feedstock above, we can work out the relevant places to check for gfortran for OSX:
- implementation: gfortran_impl_osx-64-feedstock
- activation scripts: gfortran_osx-64-feedstock
Pinning and wrappers are the same for OSX (notably there are multiple compiler wrappers on Windows). Checkout the gfortran_impl_osx-64-feedstock repository on how gfortran is built on conda-forge. You will find a patch for version 11.3.0, which needs to be checked for version 12.x first and potentially updated.