https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78549
--- Comment #30 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> --- Not quite fixed yet. I have found: ==17070== 88 bytes in 1 blocks are definitely lost in loss record 3 of 9 ==17070== at 0x4C31B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==17070== by 0x4E580E6: _gfortrani_xcalloc (memory.c:83) ==17070== by 0x503D64E: _gfortrani_open_internal4 (unix.c:1031) ==17070== by 0x503BCCB: _gfortrani_set_internal_unit (unit.c:495) ==17070== by 0x503C2E4: _gfortrani_get_unit (unit.c:556) ==17070== by 0x503A0FF: data_transfer_init (transfer.c:2680) ==17070== by 0x40122E: MAIN__ (dtio_14.f90:59) ==17070== by 0x401442: main (dtio_14.f90:41) and ==17070== at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==17070== by 0x4E58048: _gfortrani_xmalloc (memory.c:42) ==17070== by 0x5043F53: _gfortrani_fbuf_init (fbuf.c:41) ==17070== by 0x503C2F1: _gfortrani_get_unit (unit.c:557) ==17070== by 0x503A0FF: data_transfer_init (transfer.c:2680) ==17070== by 0x401004: MAIN__ (dtio_14.f90:51) ==17070== by 0x401442: main (dtio_14.f90:41) ==17070== with valgrind We are missing freeing these structures.