memory leak in doth test

So far, I've seen this only on main branch:

D:doth:Core was generated by `/builds/isc-projects/bind9/bin/named/.libs/named -D doth-ns1 -X named.lock -m r'.
D:doth:Program terminated with signal SIGABRT, Aborted.
D:doth:#0  0x00007fa6b0361afc in __pthread_kill_implementation () from /lib64/libc.so.6
D:doth:[Current thread is 1 (Thread 0x7fa6afaf55c0 (LWP 23929))]
D:doth:#0  0x00007fa6b0361afc in __pthread_kill_implementation () from /lib64/libc.so.6
D:doth:#1  0x00007fa6b03152a6 in raise () from /lib64/libc.so.6
D:doth:#2  0x00007fa6b02e87f3 in abort () from /lib64/libc.so.6
D:doth:#3  0x00007fa6b1535581 in abort () from /lib64/libtsan.so.0
D:doth:#4  0x0000000000425e4e in assertion_failed (file=<optimized out>, line=<optimized out>, type=<optimized out>, cond=<optimized out>) at main.c:237
D:doth:#5  0x00007fa6b0f5f9ce in isc_assertion_failed (file=file@entry=0x7fa6b0fb759e "mem.c", line=line@entry=1442, type=type@entry=isc_assertiontype_insist, cond=cond@entry=0x7fa6b0fbac2e "unreachable") at assertions.c:49
D:doth:#6  0x00007fa6b0f81fa3 in isc__mem_checkdestroyed () at mem.c:1442
D:doth:#7  0x00007fa6b0f8209d in mem_shutdown () at mem.c:448
D:doth:#8  0x00007fa6b15176fd in pthread_once () from /lib64/libtsan.so.0
D:doth:#9  0x00007fa6b0f7eadd in isc__mem_shutdown () at mem.c:455
D:doth:#10 0x00007fa6b0f74a65 in isc__shutdown () at lib.c:56
D:doth:#11 0x00007fa6b2021f1e in _dl_fini () at dl-fini.c:142
D:doth:#12 0x00007fa6b0317a15 in __run_exit_handlers () from /lib64/libc.so.6
D:doth:#13 0x00007fa6b0317b90 in exit () from /lib64/libc.so.6
D:doth:#14 0x00007fa6b0300447 in __libc_start_call_main () from /lib64/libc.so.6
D:doth:#15 0x00007fa6b03004f0 in __libc_start_main_impl () from /lib64/libc.so.6
D:doth:#16 0x0000000000418dd5 in _start ()