tmux build with FDEBUG, backtrace full.

        gdb ./tmux   
GNU gdb 6.8-debian
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu"...
(gdb) set follow-fork-mode child
(gdb) run
Starting program: /home/asf/dl/src/tmux-1.2/tmux 
[Thread debugging using libthread_db enabled]
[Thread debugging using libthread_db enabled]
[New Thread 0x7f3e9883c6e0 (LWP 9945)]
[Thread debugging using libthread_db enabled]
[New Thread 0x7f3e9883c6e0 (LWP 9946)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f3e9883c6e0 (LWP 9946)]
0x00007f3e97ac3a8e in ?? () from /lib/libc.so.6
(gdb) backtrace
#0  0x00007f3e97ac3a8e in ?? () from /lib/libc.so.6
#1  0x00007f3e97ac6326 in ?? () from /lib/libc.so.6
#2  0x00007f3e97ac7ad8 in malloc () from /lib/libc.so.6
#3  0x0000000000441dc2 in imsg_get (ibuf=0x19da390, imsg=0x7fffec6218f0) at compat/imsg.c:114
#4  0x0000000000428551 in server_client_msg_dispatch (c=0x19da390) at server-client.c:528
#5  0x00000000004278ac in server_client_callback (fd=7, events=2, data=0x19da390) at server-client.c:187
#6  0x00007f3e97daa538 in event_base_loop (base=0x19d9950, flags=<value optimized out>) at event.c:395
#7  0x000000000042aaf2 in server_loop () at server.c:233
#8  0x000000000042aad8 in server_start (path=0x19d4890 "/tmp//tmux-1000/default") at server.c:224
#9  0x0000000000403b5e in client_init ()
#10 0x0000000000431fa0 in main (argc=0, argv=0x7fffec623520) at tmux.c:543
(gdb) backtrace full
#0  0x00007f3e97ac3a8e in ?? () from /lib/libc.so.6
No symbol table info available.
#1  0x00007f3e97ac6326 in ?? () from /lib/libc.so.6
No symbol table info available.
#2  0x00007f3e97ac7ad8 in malloc () from /lib/libc.so.6
No symbol table info available.
#3  0x0000000000441dc2 in imsg_get (ibuf=0x19da390, imsg=0x7fffec6218f0) at compat/imsg.c:114
        av = 16000
        left = 47244640256
        datalen = 1024
#4  0x0000000000428551 in server_client_msg_dispatch (c=0x19da390) at server-client.c:528
        imsg = {hdr = {type = 14, len = 1040, flags = 0, peerid = 5, pid = 4294967295}, fd = 27105616, data = 0x7f3e9864b052}
        commanddata = {pid = 0, idx = 0, argc = -329116216, 
  argv = "�\177\000\000\002\000\000\000\002", '\0' <repeats 19 times>, "����\000\000\000\000\n", '\0' <repeats 47 times>, " \000\000\000o", '\0' <repeats 18 times>, "s\000\000\000\000\000\000\000\000\n", '\0' <repeats 47 times>, " \030b��\177\000\000\"G�\227>\177\000\000\000\000\000\000\000\000\000d", '\0' <repeats 24 times>, "�\025b��\177\000\000\000\000\000\000\000\v\000\000(\030b��\177\000\000����", '\0' <repeats 52 times>, "\030\026b��\177", '\0' <repeats 18 times>, "\001\000\000\000��\235\023��D", '\0' <repeats 29 times>, "����", '\0' <repeats 44 times>, "����"...}
        identifydata = {
  cwd = '\0' <repeats 40 times>, "�\ab��\177\000\000��D\000\000\000\000\000��D\000\000\000\000\000�\ab��\177\000\000\"G�\227>\177\000\000\000\000\000\000\000\000\000\000�\ab��\177\000\000��D\000\000\000\000\000��D\000\000\000\000\000�\ab��\177\000\000\"G�\227>\177\000\000(\ab��\177\000\000H\ab��\177", '\0' <repeats 31 times>, "\v\000\000X\ab��\177\000\000x\ab��\177\000\000�\002b��\177", '\0' <repeats 18 times>, "\200\tb��\177\000\000\233�D\000\000\000\000\000\204\006b�\004\000\000\000�\002b��\177\000\000\000\000\000\000\000\000\000\000���"..., 
  term = "�\021b��\177", '\0' <repeats 18 times>, "�\030b��\177\000\000�$D\000\000\000\000\000�\025b�\002\000\000\000\210\024b��\177\000s����\000\000\000\000����\000\000\000\000����\000\000\000\0000\022b��\177", '\0' <repeats 26 times>, "��������\027\026b�\036\000\000", flags = 4465866}
        environdata = {var = '\0' <repeats 1023 times>}
        n = 16000
        datalen = 27105616
        __func__ = "server_client_msg_dispatch"
#5  0x00000000004278ac in server_client_callback (fd=7, events=2, data=0x19da390) at server-client.c:187
        c = (struct client *) 0x19da390
#6  0x00007f3e97daa538 in event_base_loop (base=0x19d9950, flags=<value optimized out>) at event.c:395
        evsel = (const struct eventop *) 0x7f3e97fbc220
        evbase = (void *) 0x19d9f80
        tv = {tv_sec = 0, tv_usec = 999975}
        tv_p = <value optimized out>
        res = <value optimized out>
#7  0x000000000042aaf2 in server_loop () at server.c:233
No locals.
#8  0x000000000042aad8 in server_start (path=0x19d4890 "/tmp//tmux-1000/default") at server.c:224
        wp = (struct window_pane *) 0x19d4890
        pair = {6, 7}
        retval = 0
        cause = 0x0
        tv = {tv_sec = 1, tv_usec = 0}
        i = 32574
        __func__ = "server_start"
#9  0x0000000000403b5e in client_init ()
No locals.
#10 0x0000000000431fa0 in main (argc=0, argv=0x7fffec623520) at tmux.c:543
        cmdlist = (struct cmd_list *) 0x7f3e98840990
        cmd = (struct cmd *) 0x7fffec623518
        msg = MSG_COMMAND
        pw = (struct passwd *) 0x7fffec623518
        oo = (struct options *) 0x671890
        so = (struct options *) 0x671870
        wo = (struct options *) 0x6717a0
        keylist = (struct keylist *) 0x19d3960
        envdata = {path = 0x0, pid = -1, idx = 0}
        cmddata = {pid = -1, idx = 0, argc = 0, 
  argv = "\000\177\000\000\220\t\204\230>\177", '\0' <repeats 12 times>, " b����\030\000\000\000\000\000\000\000�\235<\230>\177\000\000\000\000\000\000\000\000\000\000\030\032\205\230>\177\000\000\000\000�V����\000\0006��0}�", '\0' <repeats 28 times>, "\003\000\n\000\0205b��\177\000\000(\016\204\230>\177\000\000\b\000\000\000\000\000\000\000R�td\004\000\000\000�0b��\177\000\000\0201b��\177\000\000\000\000\000\000\000\000\000\000�`c\230>\177\000\000\001\000\000\000\000\000\000\000`\025\205\230>\177\000\000�Id\230>\177", '\0' <repeats 14 times>, "\002", '\0' <repeats 19 times>, "\0201b��"...}
        s = 0x7fffec625edf "de_AT.UTF-8"
        shellcmd = 0x0
---Type <return> to continue, or q <return> to quit---
        path = 0x19d4890 "/tmp//tmux-1000/default"
        label = 0x19d4870 "\200k\235\001"
        home = 0x7fffec625a47 "/home/asf"
        cause = 0x0
        cwd = "/home/asf/dl/src/tmux-1.2", '\0' <repeats 383 times>, "O�c\230>\177", '\0' <repeats 75 times>, "`\001\000\000\000\000\000�\\\001\000\000\000\000\000�\\\001", '\0' <repeats 13 times>, "\005\000\000\000\000\000\000\000\000`!\000\000\000\000\000\000\200!\000\000\000\000\000Pr!\000\000\000\000\000p�!\000\000\000\000\000\000`\001\000\000\000\000\000\003", '\0' <repeats 111 times>, "U`d\230>\177\000\000\000\000\000\000\000\000\000\000(E\205\230>\177\000\000���\226>\177\000\0004�c\230>\177", '\0' <repeats 26 times>, "=�c\230>\177\000\000\000\000\000\000\000\000"...
        var = (char **) 0x7fffec623668
        buf = (void *) 0x7fffec622b80
        len = 2060
        opt = -1
        flags = 1
        quiet = 0
        cmdflags = 7
        events = 0
        __func__ = "main"