https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113005
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Execution timeout is: 300
spawn [open ...]
STOP 2
Internal Error: Trying to free nonempty asynchronous unit
Error termination. Backtrace:
Internal Error: Trying to free nonempty asynchronous unit
Error termination. Backtrace:
#0 0x7f986429289e in free_async_unit
at ../../../libgfortran/io/async.c:211
#1 0x7f9864288729 in close_unit_1
at ../../../libgfortran/io/unit.c:759
#2 0x401644 in ???
#3 0x7f986432cd7d in ???
#4 0x7f9863e87c90 in ???
#5 0x7f9863f07fbb in ???
#6 0xffffffffffffffff in ???
FAIL: libgomp.fortran/rwlock_1.f90 -O0 execution test
is what I see in the log. Or just STOP 2.