(gdb) bt
#0  0x00007fdd304f53a0 in pthread_kill () from /lib/libpthread.so.0
#1  0x00000000004eb8a8 in __ast_manager_event_multichan (category=2048, event=0x5b29c0 "VarSet", chancount=0, chans=0x0, file=0x5ad034 "pbx.c", line=9516,
    func=0x5b3100 "pbx_builtin_setvar_helper", fmt=0x5b29c8 "Channel: %s\r\nVariable: %s\r\nValue: %s\r\nUniqueid: %s\r\n") at manager.c:4836
#2  0x000000000051213a in pbx_builtin_setvar_helper (chan=0x1b58e68, name=0x7fdd2e6acc10 "FAXSTATUS", value=0x7fdd2e6acf59 "FAILED") at pbx.c:9510
#3  0x00007fdd2e6a662f in sendfax_exec (chan=0x1b58e68, data=0x7fdd14abc580 "/tmp/193.tiff, fs") at res_fax.c:1851
#4  0x00000000004f577c in pbx_exec (c=0x1b58e68, app=0x1a15f20, data=0x7fdd14abc580 "/tmp/193.tiff, fs") at pbx.c:1399
#5  0x00000000004ff222 in pbx_extension_helper (c=0x1b58e68, con=0x0, context=0x1b593b8 "sendfax", exten=0x1b59408 "02136314", priority=5, label=0x0,
    callerid=0x1af8ab0 "0", action=E_SPAWN, found=0x7fdd14abec70, combined_find_spawn=1) at pbx.c:4074
#6  0x0000000000500ab4 in ast_spawn_extension (c=0x1b58e68, context=0x1b593b8 "sendfax", exten=0x1b59408 "02136314", priority=5, callerid=0x1af8ab0 "0",
    found=0x7fdd14abec70, combined_find_spawn=1) at pbx.c:4566
#7  0x000000000050150d in __ast_pbx_run (c=0x1b58e68, args=0x0) at pbx.c:4664
#8  0x0000000000503097 in pbx_thread (data=0x1b58e68) at pbx.c:4975
#9  0x0000000000555d0d in dummy_start (data=0x1c24da0) at utils.c:971
#10 0x00007fdd304ef8ba in start_thread () from /lib/libpthread.so.0
#11 0x00007fdd30d2801d in clone () from /lib/libc.so.6
#12 0x0000000000000000 in ?? ()
(gdb) bt full
#0  0x00007fdd304f53a0 in pthread_kill () from /lib/libpthread.so.0
No symbol table info available.
#1  0x00000000004eb8a8 in __ast_manager_event_multichan (category=2048, event=0x5b29c0 "VarSet", chancount=0, chans=0x0, file=0x5ad034 "pbx.c", line=9516,
    func=0x5b3100 "pbx_builtin_setvar_helper", fmt=0x5b29c8 "Channel: %s\r\nVariable: %s\r\nValue: %s\r\nUniqueid: %s\r\n") at manager.c:4836
        i = {c = 0x7fdd2800a1f8, flags = 0, bucket = 0, c_version = 216, obj = 0x1c09a00, version = 215}
        session = 0x1a4cc08
        hook = 0x21
        auth = 0x7fdd14ab9b30
        cat_str = 0x7fdd14ab9b48 "dialplan,all"
        ap = {{gp_offset = 48, fp_offset = 48, overflow_arg_area = 0x7fdd14ab9d90, reg_save_area = 0x7fdd14ab9cb0}}
        now = {tv_sec = 0, tv_usec = 140587986280016}
        buf = 0x1b54270
        i = 0
        __PRETTY_FUNCTION__ = "__ast_manager_event_multichan"
#2  0x000000000051213a in pbx_builtin_setvar_helper (chan=0x1b58e68, name=0x7fdd2e6acc10 "FAXSTATUS", value=0x7fdd2e6acf59 "FAILED") at pbx.c:9510
        newvariable = 0x1c1eb20
        headp = 0x1b59218
        nametail = 0x7fdd2e6acc10 "FAXSTATUS"
        __PRETTY_FUNCTION__ = "pbx_builtin_setvar_helper"
#3  0x00007fdd2e6a662f in sendfax_exec (chan=0x1b58e68, data=0x7fdd14abc580 "/tmp/193.tiff, fs") at res_fax.c:1851
        parse = 0x588d26 "a->c"
        filenames = 0x7fdd28009610 ""
        c = 0x588df0 "internal_ao2_iterator_next"
        modems = '\000' <repeats 127 times>
        channel_alive = 304
        file_count = 838
        details = 0x588c24
        doc = 0x0
        args = {argc = 0, argv = 0x7fdd14aba028, filenames = 0x590014 "cel.c", options = 0x5a902d "\r\n"}
        opts = {flags = 0}
        info = {context = "\207C\265\001\000\000\000\000WC\265\001\000\000\000\000\207C\265\001", '\000' <repeats 44 times>"\320, \a", '\000' <repeats 13 times>,
          exten = "\000\000\373\060\335\177\000\000\000\000\000\000\000\000\000\000\377\377\377\377\000\000\000\000\200\240\253\024\335\177\000\000\300\241\253\024\335\177", '\000' <repeats 18 times>, "\003\000\000\000\000\000\000\000\377\377\377\377\000\000\000\000Ð\253\024\335\177\000",
          cid = "\262B\265\001\000\000\000\000\006\231M", '\000' <repeats 13 times>"\200, \202\265\001\000\000\000\000y\005Y\000\000\000\000\000\060\006Y\000\000\000\000\000\262B\265\001\347\001\000\000\024\000Y\000\000\000\000\000\001\200\255\373\335\177\000\000\200\202\265\001\000\000\000\000@\240\253\024\335\177\000\000i#D\000\000\000\000\000WC\265\001\000\000\000\000\006\231M\000\000\000\000\000\300\244\253\024\347\001\000\000\000\233\177\000\000\000\000"}
        __PRETTY_FUNCTION__ = "sendfax_exec"
#4  0x00000000004f577c in pbx_exec (c=0x1b58e68, app=0x1a15f20, data=0x7fdd14abc580 "/tmp/193.tiff, fs") at pbx.c:1399
        res = 32733
        u = 0x1ac0170
        saved_c_appl = 0x0
        saved_c_data = 0x0
        __PRETTY_FUNCTION__ = "pbx_exec"
#5  0x00000000004ff222 in pbx_extension_helper (c=0x1b58e68, con=0x0, context=0x1b593b8 "sendfax", exten=0x1b59408 "02136314", priority=5, label=0x0,
    callerid=0x1af8ab0 "0", action=E_SPAWN, found=0x7fdd14abec70, combined_find_spawn=1) at pbx.c:4074
        e = 0x1b85480
        app = 0x1a15f20
        res = 27572064
        q = {incstack = {0x0 <repeats 128 times>}, stacklen = 0, status = 5, swo = 0x0, data = 0x0, foundcontext = 0x1b593b8 "sendfax"}
---Type <return> to continue, or q <return> to quit---
        passdata = "/tmp/193.tiff, fs\000nid)=+49.30.89095300\000s Fax\000\177\000\000\360ʫ\024\335\177\000\000\000\000\000\000\321\006\000\000\037\000\000\000\000\000\000\000\377\377\377\377\377\377\377\377\020ϫ\024\000\000\000\000\000\000\000\000\335\177\000\000\000\000\000\000\063\061\070\062\020ϫ\024\335\177\000\000 ϫ\024\335\177\000\000\020ϫ\024\000\000\000\000\020ϫ\024\335\177\000\000\024ϫ\024\000\000\000\000\000\000\000\000\335\177\000\000\020ϫ\024\001\000\000\000/ϫ\024\335\177", '\000' <repeats 42 times>"\377, \377\377\377\000\000\000\000\250Y\312\060\335\177\000\000s\000\000\000\060\000\000\000hʫ\024\335\177\000\000\262\314Z", '\000' <repeats 13 times>, "og/log-1\000\000\000\000\000\000\000\000"...
        matching_action = 0
        __PRETTY_FUNCTION__ = "pbx_extension_helper"
#6  0x0000000000500ab4 in ast_spawn_extension (c=0x1b58e68, context=0x1b593b8 "sendfax", exten=0x1b59408 "02136314", priority=5, callerid=0x1af8ab0 "0",
    found=0x7fdd14abec70, combined_find_spawn=1) at pbx.c:4566
No locals.
#7  0x000000000050150d in __ast_pbx_run (c=0x1b58e68, args=0x0) at pbx.c:4664
        digit = 0
        invalid = 0
        timeout = 0
        dst_exten = '\000' <repeats 80 times>"\370, \377\377\377\377\377\377\377\001", '\000' <repeats 31 times>, "\020\001\000\000\000\000\000\000\a", '\000' <repeats 15 times>, "\001\000\000\000\000\000\000\000[\370N0\335\177\000\000\000\000\000\000\000\000\000\000\370\377\377\377\377\377\377\377\001\000\000\000\000\000\000\000\020\000\000\000\000\000\000\000\033\377\001", '\000' <repeats 14 times>"\356, \253\024\335\177\000\000\300\354\253\024\335\177\000\000\360\355\253\024\335\177\000\000\200\375\253\024\335\177\000\000\320\353\253\024\335\177\000\000\300hO0\335\177\000"
        pos = 0
        found = 1
        res = 0
        autoloopflag = 0
        error = 0
        __PRETTY_FUNCTION__ = "__ast_pbx_run"
#8  0x0000000000503097 in pbx_thread (data=0x1b58e68) at pbx.c:4975
        c = 0x1b58e68
#9  0x0000000000555d0d in dummy_start (data=0x1c24da0) at utils.c:971
        __cancel_buf = {__cancel_jmp_buf = {{__cancel_jmp_buf = {0, 2107027356282262588, 140587510288064, 140587511314192, 140587988516928, 3, 2107027356273873980,
                -2123583791725538244}, __mask_was_saved = 0}}, __pad = {0x7fdd14abef80, 0x0, 0x7fdd30700280, 0x0}}
        __cancel_routine = 0x4379e9 <ast_unregister_thread>
        __cancel_arg = 0x7fdd14abf710
        not_first_call = 0
        ret = 0x7fdd30fb0870
        a = {start_routine = 0x503072 <pbx_thread>, data = 0x1b58e68, name = 0x1ac2460 "pbx_thread", ' ' <repeats 11 times>, "started at [ 4996] pbx.c ast_pbx_start()"}
#10 0x00007fdd304ef8ba in start_thread () from /lib/libpthread.so.0
No symbol table info available.
#11 0x00007fdd30d2801d in clone () from /lib/libc.so.6
No symbol table info available.
#12 0x0000000000000000 in ?? ()
No symbol table info available.