Other compilers such as g95, NAG f95 and ifort also search /usr/local/include and /usr/include for .mod files (and "INCLUDE"d files).
I think gfortran should do the same, especially since #include searches these paths and "man gfortran"'s -Idir description implies #include and include search the same directories. g95 seems to use libcpp for reading almost all files and thus it searches also in /usr/include (cpp_create_reader, cpp_read_main_file etc.). That way one could also cpp-preprocess files included via "INCLUDE" rather than via "#include". The system include path is in the variable GCC_INCLUDE_DIR, which does not seem to be used outside of cpp unless I missed something. For CPP work, see wiki: http://gcc.gnu.org/wiki/GFortran44 -- Summary: Search /usr/local/include and /usr/include for .mod files Product: gcc Version: 4.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: burnus at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35707
