Figured I'd give 3.2.0 a whirl, but sadly it still seems quite assertion-failure-prone. It seems to hit quite a few assertions, sadly, so not sure if the underlying issue isn't something less than deterministic. I have core dumps that I can provide against the debian forky 3.2.0 package. I saw at least the following: (gdb) bt #0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at ./nptl/pthread_kill.c:44 #1 0x00007fa1b85289ff in __pthread_kill_internal (threadid=<optimized out>, signo=6) at ./nptl/pthread_kill.c:89 #2 0x00007fa1b84d3cc2 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 #3 0x00007fa1b84bc4ac in __GI_abort () at ./stdlib/abort.c:77 #4 0x0000555dddb0a1bc in bug (msg=msg@entry=0x555dddb1ace8 "Assertion '%s' failed at %s:%d") at sysdep/unix/log.c:412 #5 0x0000555ddda7ad4c in proto_announce_state_locked (ts=0x555dddb9a260 <proto_state_table_pub>, p=0x555e06438c70, new_state=0x7fa111f18208) at nest/proto.c:3069 #6 proto_announce_state (p=0x555e06438c70, attr=0x7fa111f18208) at nest/proto.c:3129 #7 0x0000555ddda58cb6 in defer_execute (_ld=<optimized out>) at lib/defer.c:22 #8 0x0000555ddda590a6 in ev_run_list_limited (l=l@entry=0x555dddb94578 <main_birdloop+216>, limit=4294967294, limit@entry=0) at lib/event.c:336 #9 0x0000555dddb007a4 in io_loop () at sysdep/unix/io.c:2648 #10 0x0000555ddda1632e in main (argc=<optimized out>, argv=<optimized out>) at sysdep/unix/main.c:1106 and this twice: (gdb) bt #0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at ./nptl/pthread_kill.c:44 #1 0x00007facbfb6c9ff in __pthread_kill_internal (threadid=<optimized out>, signo=6) at ./nptl/pthread_kill.c:89 #2 0x00007facbfb17cc2 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 #3 0x00007facbfb004ac in __GI_abort () at ./stdlib/abort.c:77 #4 0x0000557b139b21bc in bug (msg=msg@entry=0x557b139c2ce8 "Assertion '%s' failed at %s:%d") at sysdep/unix/log.c:412 #5 0x0000557b13934353 in rt_notify_basic (c=c@entry=0x557b1d7e2e10, new=<optimized out>, new@entry=0x7fac024adfb8, old=old@entry=0x7fac8828a938) at nest/rt-table.c:1192 #6 0x0000557b139385cb in channel_notify_basic (_channel=0x557b1d7e2e10) at nest/rt-table.c:1627 #7 0x0000557b139010a6 in ev_run_list_limited (l=l@entry=0x557b1d7e37d8, limit=4294967294, limit@entry=4294967295) at lib/event.c:336 #8 0x0000557b139af4ff in birdloop_run (_loop=0x557b1d7e3700) at sysdep/unix/io-loop.c:1836 #9 0x0000557b139010a6 in ev_run_list_limited (l=0x557b1d898fb8, limit=4294967294, limit@entry=4294967295) at lib/event.c:336 #10 0x0000557b139ad392 in bird_thread_main (arg=0x557b1d899210) at sysdep/unix/io-loop.c:952 #11 0x00007facbfb6ab7b in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:448 #12 0x00007facbfbe87b8 in __GI___clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78 I also got a Assertion '!new || rte_is_valid(new)' failed at nest/rt-table.c:1416 once but don't have a coredump for that one.