getdns_context_destroy crashes

[mistr]

When the request created by a getdns_general call invoces the callbackfn with GETDNS_CALLBACK_TIMEOUT then calling of getdns_context_destroy immediately after the event_base_loop crashes. The sample code is at gitlab. Schematically:

getdns_general(context, ..., callbackfn);
event_base_loop(...); // callbackfn(GETDNS_CALLBACK_TIMEOUT) invocation
getdns_context_destroy(context); // CRASH!!! Segmentation fault (core dumped)

Getdns (Ubuntu 20.04; getdns branch develop) is configured with -DENABLE_UNBOUND_EVENT_API=ON and -DBUILD_LIBEVENT2=ON.

Is this behaviour an error, or should I call event_base_loop repeatedly until it returns 1? But if I have multiple requests at the same time, how do I know when to call getdns_context_destroy?

Gdb invocation:

gdb ./getdns-demo core

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Reading symbols from ./getdns-demo...
[New LWP 1094016]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `./getdns-demo'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  clear_my_event (ev=0x55add90e9210) at /home/user/projects/getdns-demo/3rd-party/getdns/src/ub_loop.c:153
153     (ev)->loop->extension->vmt->clear((ev)->loop->extension, &(ev)->gev);
(gdb) bt
#0  clear_my_event (ev=0x55add90e9210) at /home/user/projects/getdns-demo/3rd-party/getdns/src/ub_loop.c:153
#1  0x000055add761dfb8 in my_event_del (ev=0x55add90e9210) at /home/user/projects/getdns-demo/3rd-party/getdns/src/ub_loop.c:299
#2  0x00007f7bbf46308c in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#3  0x00007f7bbf46a9ae in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#4  0x00007f7bbf416257 in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#5  0x00007f7bbf3fe37e in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#6  0x00007f7bbf4126c9 in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#7  0x00007f7bbf4141f3 in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#8  0x00007f7bbf4142d9 in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#9  0x00007f7bbf3ed748 in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#10 0x00007f7bbf3eecd2 in ?? () from /lib/x86_64-linux-gnu/libunbound.so.8
#11 0x00007f7bbf3e9bcb in ub_ctx_delete () from /lib/x86_64-linux-gnu/libunbound.so.8
#12 0x000055add75ecaea in getdns_context_destroy (context=0x55add8dcfb40) at /home/user/projects/getdns-demo/3rd-party/getdns/src/context.c:1670
#13 0x000055add75e8494 in resolve_cdnskey_record (domain=<optimized out>, timeout_ms=<optimized out>, break_loop_if_solved=1) at /home/user/projects/getdns-demo/src/main.c:78
#14 0x000055add75e8049 in main () at /home/user/projects/getdns-demo/src/main.c:20