How to fix 'need fortran-95+TR-15581/fortran-2003 compiler, not f77. Stop.'

Problem:

While trying to compile a software, you see this error message:

makefile:252: *** need fortran-95+TR-15581/fortran-2003 compiler, not f77.  Stop.

Solution

Run

export FC=gfortran

then retry the command that caused the error (e.g. make)