https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83613
--- Comment #6 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> --- Try this patch: diff --git a/libgfortran/io/unit.c b/libgfortran/io/unit.c index 2ca8525fbec..a655665aa8a 100644 --- a/libgfortran/io/unit.c +++ b/libgfortran/io/unit.c @@ -707,7 +707,9 @@ init_units (void) } /* The default internal units. */ u = insert_unit (GFC_INTERNAL_UNIT); + __gthread_mutex_unlock (&u->lock); u = insert_unit (GFC_INTERNAL_UNIT4); + __gthread_mutex_unlock (&u->lock); }