http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59395
--- Comment #3 from janus at gcc dot gnu.org --- The backtrace is: 0x8a95ff crash_signal /home/jweil/gcc48/branch/gcc/toplev.c:332 0x5bd997 free_components /home/jweil/gcc48/branch/gcc/fortran/symbol.c:2068 0x5bd997 gfc_free_symbol(gfc_symbol*) /home/jweil/gcc48/branch/gcc/fortran/symbol.c:2496 0x5bdb43 free_sym_tree /home/jweil/gcc48/branch/gcc/fortran/symbol.c:3302 0x5bdb31 free_sym_tree /home/jweil/gcc48/branch/gcc/fortran/symbol.c:3299 0x5bdb3a free_sym_tree /home/jweil/gcc48/branch/gcc/fortran/symbol.c:3300 0x5bd80a gfc_free_namespace(gfc_namespace*) /home/jweil/gcc48/branch/gcc/fortran/symbol.c:3465 0x5bddaf gfc_symbol_done_2() /home/jweil/gcc48/branch/gcc/fortran/symbol.c:3507 0x57a678 gfc_done_2() /home/jweil/gcc48/branch/gcc/fortran/misc.c:267 0x58dde9 translate_all_program_units /home/jweil/gcc48/branch/gcc/fortran/parse.c:4493 0x58dde9 gfc_parse_file() /home/jweil/gcc48/branch/gcc/fortran/parse.c:4688 0x5c9cc5 gfc_be_parse_file /home/jweil/gcc48/branch/gcc/fortran/f95-lang.c:189 where line 2068 of symbol.c is: free (p->tb); It seems that tb is the same for the components 'a' and 'b', which leads to the double free.