I have updated to macOS Big Sur Version 11.6 . I am not able to compile simple fortran code now using  gfortran hello_world.F90  ld: unexpected token: !tapi-tbd file '/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd' for architecture x86_64 collect2: error: ld returned 1 exit status xxxx-MacBook-Pro-2:fortran xxxxx$ which gfortran /usr/local/bin/gfortran I found that it is the issue from macOS. I have tried many online forum suggestions but it didn't work. Is there a fix ?