(gdb) bt full
#0  0x00007f37c8f60407 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
        resultvar = 0
        pid = 2998
        selftid = 3018
#1  0x00007f37c8f617e8 in __GI_abort () at abort.c:89
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x7fffac98e495, sa_sigaction = 0x7fffac98e495}, sa_mask = {
            __val = {139877572723147, 139877569013792, 193, 4, 139877558143472, 3, 51, 0, 0, 0, 0, 21474836480,
              139877572722673, 139877558143624, 139877581746176, 139877572738328}}, sa_flags = -925882330,
          sa_restorer = 0x7f37c8d02880 <__PRETTY_FUNCTION__.4367>}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00007f37c8f59526 in __assert_fail_base (fmt=0x7f37c908fd18 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",
    assertion=assertion@entry=0x7f37c8d02826 "*lock == ((ath_mutex_t) 0)",
    file=file@entry=0x7f37c8d02820 "ath.c", line=line@entry=193,
    function=function@entry=0x7f37c8d02880 <__PRETTY_FUNCTION__.4367> "_gcry_ath_mutex_lock") at assert.c:92
        str = 0x7f37b800a340 ""
        total = 4096
#3  0x00007f37c8f595d2 in __GI___assert_fail (
    assertion=assertion@entry=0x7f37c8d02826 "*lock == ((ath_mutex_t) 0)",
    file=file@entry=0x7f37c8d02820 "ath.c", line=line@entry=193,
    function=function@entry=0x7f37c8d02880 <__PRETTY_FUNCTION__.4367> "_gcry_ath_mutex_lock") at assert.c:101
No locals.
#4  0x00007f37c8cbcb2a in _gcry_ath_mutex_lock (lock=0x7f37c8f2ab98 <digests_registered_lock>) at ath.c:193
        __PRETTY_FUNCTION__ = "_gcry_ath_mutex_lock"
#5  0x00007f37c8cc9b8f in md_digest_length (algorithm=algorithm@entry=2) at md.c:1077
        digest = <optimized out>
        mdlen = 0
#6  0x00007f37c8cca28d in md_final (a=a@entry=0x7f37b80088d8) at md.c:835
        om = 0x7f37b8007408
        err = <optimized out>
        algo = 2
        p = 0x7f37b8007440 "+܂\023\060\346\033\233\330\060\265%\253vɕZl\321\035,\235\326E"
        dlen = <optimized out>
        r = <optimized out>
#7  0x00007f37c8ccadbf in md_final (a=0x7f37b80088d8) at md.c:819
No locals.
#8  _gcry_md_ctl (hd=hd@entry=0x7f37b80088d8, cmd=cmd@entry=5, buffer=buffer@entry=0x0, buflen=buflen@entry=0)
    at md.c:897
        rc = GPG_ERR_NO_ERROR
#9  0x00007f37c8ccade9 in _gcry_md_read (hd=0x7f37b80088d8, algo=algo@entry=2) at md.c:983
No locals.
#10 0x00007f37c8cb4da5 in gcry_md_read (hd=<optimized out>, algo=algo@entry=2) at visibility.c:833
No locals.
#11 0x00007f37c94facce in otrl_proto_accept_data (plaintextp=0x7f37c82a4d38, tlvsp=0x7f37c82a4d30,
    context=0x7f37b8001640, datamsg=<optimized out>, flagsp=<optimized out>,
    extrakey=0x7f37b8004c38 <incomplete sequence \370>) at proto.c:830
        otrtag = <optimized out>
        endtag = <optimized out>
        err = <optimized out>
        rawmsg = 0x7f37b800a110 ""
        msglen = <optimized out>
        rawlen = <optimized out>
        lenp = <optimized out>
        macstart = 0x7f37b800a110 ""
        macend = 0x7f37b800a204 "\262f\266\373\206\206\220S\242:\230\021>]\377\366\070Nr\200"
        bufp = <optimized out>
        sender_keyid = <optimized out>
        recipient_keyid = <optimized out>
        sender_next_y = 0x7f37b800a248
        ctr = "\000\000\000\000\000\000\000\001"
        datalen = 16
        reveallen = <optimized out>
        data = 0x7f37b8004e90 "\252\230\\\265\177\065\233\325۩\241M\257\233\253", <incomplete sequence \327>
        nul = 0x0
        givenmac = "\262f\266\373\206\206\220S\242:\230\021>]\377\366\070Nr\200"
        sess = <optimized out>
        version = <optimized out>
#12 0x00007f37c94ff071 in otrl_message_receiving (us=0xbb6, ops=0xbca, ops@entry=0x7f37c9b33040 <ops>,
    opdata=0x6, opdata@entry=0x7f37c82a4e60, accountname=0x7f37c9930f5e "bob",
    protocol=0x7f37c9930e92 "otr-test", sender=0x7f37c9930f58 "alice",
    message=0x7f37c0005b50 "?OTR:AAMDQAF1BTgTxWYAAAAAAgAAAAMAAADAjZAJSbkG5PZOT9bUzeL3a5GwK/r4hie8UJ8Rn/MttDbWlk4sPrtsGwQEjaPiWUaOP4xcZaHIzZPwo2bMEMEGRSNkp8yo+1Km9JVzd/2+QfwQkgjts4E33Tp81WTpLEsEla1R8/ah3fDKXOFq7wkz90fBfNhAU7u1lZD"..., newmessagep=0x7f37c82a4e00, tlvsp=0x7f37c82a4e10, contextp=0x0, add_appdata=0x7f37b8004c38, data=0x0)
    at message.c:1336
        plaintext = 0x0
---Type <return> to continue, or q <return> to quit---
        err_msg = 0x7f37c0005b50 "?OTR:AAMDQAF1BTgTxWYAAAAAAgAAAAMAAADAjZAJSbkG5PZOT9bUzeL3a5GwK/r4hie8UJ8Rn/MttDbWlk4sPrtsGwQEjaPiWUaOP4xcZaHIzZPwo2bMEMEGRSNkp8yo+1Km9JVzd/2+QfwQkgjts4E33Tp81WTpLEsEla1R8/ah3fDKXOFq7wkz90fBfNhAU7u1lZD"...
        flags = 0 '\000'
        tlvs = 0x0
        extrakey = 0x7f37b8004c38 <incomplete sequence \370>
        nextMsg = 3221248848
        endwhite = 0x7f37c901f0d5 <___fprintf_chk+245> "\205\355\211ƋSt~\006\203\342\373\211St\203\342\353\367\003"
        haveauthmsg = -922619691
        bestversion = 3381857938
        startwhite = 0x1 <Address 0x1 out of bounds>
        context_added = 0
        unfragmessage = 0x0
        edata = {gone_encrypted = 0, us = 0x7f37c9da9090, ops = 0x7f37c9b33040 <ops>, opdata = 0x7f37c82a4e60,
          context = 0x7f37b8001640, ignore_message = -1, messagep = 0x7f37c82a4e00}
        our_instance = 940819814
        their_instance = 1073837317
        version = 8
#13 0x00007f37c992f7a9 in recv_otr_msg (sock=sock@entry=9, to=to@entry=0x7f37c9930f5e "bob",
    from=from@entry=0x7f37c9930f58 "alice", oinfo=oinfo@entry=0x7f37c82a4e60) at client.c:375
        err = <optimized out>
        new_msg = 0x0
        omsg = 0x7f37c0004770
        tlvs = 0x0
#14 0x00007f37c9930021 in bob_thread (data=<optimized out>) at client.c:621
        fd = <optimized out>
        event = <optimized out>
        i = 0
        timeout = <optimized out>
        nb_fd = 1
        ev = {{events = 1, data = {ptr = 0x9, fd = 9, u32 = 9, u64 = 9}}, {events = 0, data = {ptr = 0x0,
              fd = 0, u32 = 0, u64 = 0}}, {events = 0, data = {ptr = 0x0, fd = 0, u32 = 0, u64 = 0}}}
        sock_to_alice = <optimized out>
        sock_from_alice = 9
        epfd = 5
        ret = <optimized out>
        oinfo = {sock = 6}
#15 0x00007f37c92dc0a4 in start_thread (arg=0x7f37c82a5700) at pthread_create.c:309
        __res = <optimized out>
        pd = 0x7f37c82a5700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {139877558146816, -1842732102029076492, 0, 139877581762656,
                0, 139877558146816, 1730187915542730740, 1730190059099068404}, mask_was_saved = 0}}, priv = {
            pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#16 0x00007f37c901104d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111