FFLAGS ------ Default compilation flags to be used when compiling ``Fortran`` files. Will only be used by CMake on the first configuration to determine ``Fortran`` default compilation flags, after which the value for ``FFLAGS`` is stored in the cache as :variable:`CMAKE_Fortran_FLAGS _FLAGS>`. For any configuration run (including the first), the environment variable will be ignored if the :variable:`CMAKE_Fortran_FLAGS _FLAGS>` variable is defined.