https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83613
--- Comment #3 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- > Can you try this and report: > ... It does not work without the patch --- ../_clean/libgfortran/io/unit.c 2017-12-14 10:02:30.000000000 +0100 +++ libgfortran/io/unit.c 2017-12-29 00:28:42.000000000 +0100 @@ -706,8 +706,8 @@ init_units (void) __gthread_mutex_unlock (&u->lock); } /* The default internal units. */ - u = insert_unit (GFC_INTERNAL_UNIT); - u = insert_unit (GFC_INTERNAL_UNIT4); +/* u = insert_unit (GFC_INTERNAL_UNIT); + u = insert_unit (GFC_INTERNAL_UNIT4); */ } What is "fixed" by the lines u = insert_unit (GFC_INTERNAL_UNIT); u = insert_unit (GFC_INTERNAL_UNIT4); ?