assertion failure in req_senddone

Job #2037401 failed for c177c33c:

D:checkds:Core was generated by `/builds/isc-projects/bind9/bin/named/.libs/named -D checkds-ns9 -X named.lock -'.
D:checkds:Program terminated with signal SIGABRT, Aborted.
D:checkds:#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
D:checkds:[Current thread is 1 (Thread 0x7f81a97fa700 (LWP 1941))]
D:checkds:#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
D:checkds:#1  0x00007f81b069e535 in __GI_abort () at abort.c:79
D:checkds:#2  0x0000000000420cac in assertion_failed (file=0x7f81b12ee461 "request.c", line=<optimized out>, type=<optimized out>, cond=<optimized out>) at main.c:237
D:checkds:#3  0x00007f81b1372b7a in isc_assertion_failed (file=0x2 <error: Cannot access memory at address 0x2>, line=-1451276416, line@entry=1029, type=type@entry=isc_assertiontype_require, cond=0x7f81b06b37bb <__GI_raise+267> "H\213\214$\b\001") at assertions.c:47
D:checkds:#4  0x00007f81b123b4e2 in req_senddone (eresult=<optimized out>, region=<optimized out>, arg=<optimized out>) at request.c:1029
D:checkds:#5  0x00007f81b11727f6 in send_done (handle=0x7f819db70d80, result=ISC_R_CANCELED, cbarg=<optimized out>) at dispatch.c:1770
D:checkds:#6  0x00007f81b1363b7f in isc__nm_async_sendcb (worker=<optimized out>, ev0=ev0@entry=0x7f81a5843580) at netmgr/netmgr.c:2788
D:checkds:#7  0x00007f81b13603c6 in process_netievent (worker=worker@entry=0x7f81adc4a030, ievent=ievent@entry=0x7f81a5843580) at netmgr/netmgr.c:960
D:checkds:#8  0x00007f81b135baf1 in process_queue (worker=0x7f81adc4a030, type=NETIEVENT_NORMAL) at netmgr/netmgr.c:998
D:checkds:#9  process_all_queues (worker=0x7f81adc4a030) at netmgr/netmgr.c:746
D:checkds:#10 async_cb (handle=0x7f81adc4a390) at netmgr/netmgr.c:775
D:checkds:#11 0x00007f81b0c976d8 in ?? () from /usr/lib/x86_64-linux-gnu/libuv.so.1
D:checkds:#12 0x00007f81b0ca6530 in uv.io_poll () from /usr/lib/x86_64-linux-gnu/libuv.so.1
D:checkds:#13 0x00007f81b0c97ff5 in uv_run () from /usr/lib/x86_64-linux-gnu/libuv.so.1
D:checkds:#14 0x00007f81b135bc39 in nm_thread (worker0=0x7f81adc4a030) at netmgr/netmgr.c:681
D:checkds:#15 0x00007f81b13a1aea in isc__trampoline_run (arg=0x1948b00) at trampoline.c:185
D:checkds:#16 0x00007f81b0844fa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
D:checkds:#17 0x00007f81b07754cf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f81a97fa700 (LWP 1941)):
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
        set = {__val = {16387, 0, 0, 0, 3905522674892552757, 140195000463360, 140195000513668, 140195000691568, 140195006326720, 140194998247424, 0, 140194998247424, 140194871224000, 140194942605624, 140194942605616, 5}}
        pid = <optimized out>
        tid = <optimized out>
        ret = <optimized out>
#1  0x00007f81b069e535 in __GI_abort () at abort.c:79
        save_stage = 1
        act = {__sigaction_handler = {sa_handler = 0x7f81b0c5e900, sa_sigaction = 0x7f81b0c5e900}, sa_mask = {__val = {140194987098112, 140194987177249, 140194988119184, 140195000149089, 140194871199616, 31, 1483, 140194175012544, 13, 140194993269024, 17674366533170704384, 206158430256, 4575977, 140195000149089, 14, 206158430248}}, sa_flags = -1451275824, sa_restorer = 0xe}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x0000000000420cac in assertion_failed (file=0x7f81b12ee461 "request.c", line=<optimized out>, type=<optimized out>, cond=<optimized out>) at main.c:237
        tracebuf = {0x420cc4 <assertion_failed+148>, 0x7f81b1372b7a <isc_assertion_failed+10>, 0x7f81b123b4e2 <req_senddone+450>, 0x7f81b11727f6 <send_done+54>, 0x7f81b1363b7f <isc__nm_async_sendcb+143>, 0x7f81b13603c6 <process_netievent+1222>, 0x7f81b135baf1 <async_cb+145>, 0x7f81b0c976d8, 0x7f81b0ca6530 <uv.io_poll+800>, 0x7f81b0c97ff5 <uv_run+277>, 0x7f81b135bc39 <nm_thread+121>, 0x7f81b13a1aea <isc__trampoline_run+74>, 0x7f81b0844fa3 <start_thread+243>, 0x7f81b07754cf <clone+63>, 0x7f81b07754cf <clone+63>, 0x0, 0x0, 0x405, 0x7f81b12ee461, 0x7f81a576f990, 0x7f81b0679668, 0x7f819c2b4e00, 0x7f81adc4a030, 0x7f81b18e2b00 <_dl_fixup+208>, 0x5, 0xffff00001f80, 0x7f816e473000, 0xa0, 0x7f819ca05748, 0x7f81a97f4e10, 0x0, 0x7f81a97f9080, 0x7f819ca05708, 0x7f81b043efaf, 0x7f81ade5f740, 0x7f81adea5040, 0x7f81adedc6c0, 0x7f81adedc6c0, 0x7f81adedc6c0, 0x7f81adedd340, 0x7f81adedd340, 0x7f81adedd440, 0xdededededededede, 0xdededededededede, 0xff00ffff00ff00, 0xff00ff00ff00ff, 0xff000000, 0x0, 0x3036346536313866, 0x756873203a303034, 0x0, 0x10, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x7325732500732520, 0x7325732573257325, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4200000042, 0x4200000042, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x7f81adc09000, 0x7f816e460400, 0x7f81b138437b <isc__mem_put+171>, 0x0, 0x7f816e460400, 0x7f819da00000, 0x7f816e460410, 0x0, 0x1, 0x7f816e460560, 0x7f816e460410, 0x2, 0x800000000000000e, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x7f81a97f4e70, 0x7f81b1171054 <tcp_recv+1828>, 0x7f81a56e2000, 0x700350a1f640002, 0x0 <repeats 15 times>, 0x10, 0xffffffffffffffff, 0xffffffffffffffff, 0x700350a1f640002, 0x0, 0x0, 0x0, 0x0, 0xf547f6b817b13000, 0x0, 0x7f81adc09000, 0x7f81a97f4e10, 0x7f81b13ac7a8, 0x7b0, 0x7f81adc09008}
        nframes = <optimized out>
#3  0x00007f81b1372b7a in isc_assertion_failed (file=0x2 <error: Cannot access memory at address 0x2>, line=-1451276416, line@entry=1029, type=type@entry=isc_assertiontype_require, cond=0x7f81b06b37bb <__GI_raise+267> "H\213\214$\b\001") at assertions.c:47
No locals.
#4  0x00007f81b123b4e2 in req_senddone (eresult=<optimized out>, region=<optimized out>, arg=<optimized out>) at request.c:1029
        request = <optimized out>
#5  0x00007f81b11727f6 in send_done (handle=0x7f819db70d80, result=ISC_R_CANCELED, cbarg=<optimized out>) at dispatch.c:1770
        resp = 0x0
#6  0x00007f81b1363b7f in isc__nm_async_sendcb (worker=<optimized out>, ev0=ev0@entry=0x7f81a5843580) at netmgr/netmgr.c:2788
        ievent = <optimized out>
        sock = 0x7f816e473000
        uvreq = 0x0
        eresult = ISC_R_CANCELED
#7  0x00007f81b13603c6 in process_netievent (worker=worker@entry=0x7f81adc4a030, ievent=ievent@entry=0x7f81a5843580) at netmgr/netmgr.c:960
No locals.
#8  0x00007f81b135baf1 in process_queue (worker=0x7f81adc4a030, type=NETIEVENT_NORMAL) at netmgr/netmgr.c:998
        waiting = 4
        ievent = 0x7f81a5843580
        stop = <optimized out>
#9  process_all_queues (worker=0x7f81adc4a030) at netmgr/netmgr.c:746
        result = <optimized out>
        type = 3
        reschedule = true
        type = <optimized out>
        result = <optimized out>
#10 async_cb (handle=0x7f81adc4a390) at netmgr/netmgr.c:775
        worker = 0x7f81adc4a030
#11 0x00007f81b0c976d8 in ?? () from /usr/lib/x86_64-linux-gnu/libuv.so.1
No symbol table info available.
#12 0x00007f81b0ca6530 in uv.io_poll () from /usr/lib/x86_64-linux-gnu/libuv.so.1
No symbol table info available.
#13 0x00007f81b0c97ff5 in uv_run () from /usr/lib/x86_64-linux-gnu/libuv.so.1
No symbol table info available.
#14 0x00007f81b135bc39 in nm_thread (worker0=0x7f81adc4a030) at netmgr/netmgr.c:681
        r = <optimized out>
        worker = 0x7f81adc4a030
        mgr = 0x7f81adc45000
#15 0x00007f81b13a1aea in isc__trampoline_run (arg=0x1948b00) at trampoline.c:185
        trampoline = 0x1948b00
        result = <optimized out>
#16 0x00007f81b0844fa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
        ret = <optimized out>
        pd = <optimized out>
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140194871224064, -130959809494454272, 140721831580654, 140721831580655, 140194871224064, 26512128, 84985927855435776, 84967749757497344}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#17 0x00007f81b07754cf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
No locals.