http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54725
--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-09-28 14:30:09 UTC --- I forgot half of the patch - the second half is needed when no system root exists. The patch is still untested. --- a/gcc/fortran/cpp.c +++ b/gcc/fortran/cpp.c @@ -40,2 +40,6 @@ along with GCC; see the file COPYING3. If not see +#ifndef TARGET_SYSTEM_ROOT +# define TARGET_SYSTEM_ROOT NULL +#endif + #ifndef TARGET_CPU_CPP_BUILTINS @@ -269,3 +273,3 @@ gfc_cpp_init_options (unsigned int decoded_options_count, gfc_cpp_option.prefix = NULL; - gfc_cpp_option.sysroot = NULL; + gfc_cpp_option.sysroot = TARGET_SYSTEM_ROOT;