xorg-server-1.12.2 caught SIGABRT once when exiting. I don't remember any non usual configuration or things that happened or I have done. I cannot reproduce it anymore. Just reporting it with a backtrace because I think someone might have an idea what went wrong and be able to fix it.

Core was generated by `/usr/bin/X -br -novtswitch -quiet :0 vt7 -nolisten tcp -auth /var/run/xauth/A:0'.
Program terminated with signal 6, Aborted.
#0  0x00007fa97c2aa885 in *__GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
64      ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) thread apply all bt full

Thread 1 (Thread 0x7fa97e081880 (LWP 8719)):
#0  0x00007fa97c2aa885 in *__GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
        resultvar = 0
        pid = 8719
        selftid = <optimized out>
#1  0x00007fa97c2abd06 in *__GI_abort () at abort.c:91
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x7fff041a3380, sa_sigaction = 0x7fff041a3380}, sa_mask = {__val = {140733262214000, 140733262223369, 10, 
              140365910636849, 3, 140733262214010, 6, 140365910636853, 2, 140733262213998, 2, 140365910627954, 1, 140365910636849, 3, 140733262214004}}, 
          sa_flags = 12, sa_restorer = 0x7fa97c3df935}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00007fa97c2e9dd7 in __libc_message (do_abort=2, fmt=0x7fa97c3e1230 "*** glibc detected *** %s: %s: 0x%s ***\n") at ../sysdeps/unix/sysv/linux/libc_fatal.c:198
        ap = {{gp_offset = 40, fp_offset = 48, overflow_arg_area = 0x7fff041a3cf0, reg_save_area = 0x7fff041a3c00}}
        ap_copy = {{gp_offset = 16, fp_offset = 48, overflow_arg_area = 0x7fff041a3cf0, reg_save_area = 0x7fff041a3c00}}
        fd = 13
        on_2 = <optimized out>
        list = <optimized out>
        nlist = <optimized out>
        cp = <optimized out>
        written = <optimized out>
#3  0x00007fa97c2ef2f6 in malloc_printerr (action=3, str=0x7fa97c3e1630 "free(): invalid next size (fast)", ptr=<optimized out>) at malloc.c:5007
        buf = "00000000022ffff0"
        cp = <optimized out>
#4  0x00000000004534be in AccelerationDefaultCleanup (dev=0x2300030) at /var/tmp/portage/x11-base/xorg-server-1.12.2/work/xorg-server-1.12.2/dix/ptrveloc.c:173
        vel = <optimized out>
#5  0x00000000004295e9 in CloseDevice (dev=0x2300030) at /var/tmp/portage/x11-base/xorg-server-1.12.2/work/xorg-server-1.12.2/dix/devices.c:901
        screen = 0x20ca260
        classes = <optimized out>
        j = <optimized out>
#6  0x000000000042d805 in RemoveDevice (dev=0x2300030, sendevent=1 '\001') at /var/tmp/portage/x11-base/xorg-server-1.12.2/work/xorg-server-1.12.2/dix/devices.c:1084
        prev = <optimized out>
        tmp = 0x2300030
        next = <optimized out>
        ret = <optimized out>
        screen = <optimized out>
        deviceid = 13
        initialized = 1
        flags = {0 <repeats 13 times>, 8, 0 <repeats 26 times>}
#7  0x0000000000483d61 in DeleteInputDeviceRequest (pDev=0x2300030)
    at /var/tmp/portage/x11-base/xorg-server-1.12.2/work/xorg-server-1.12.2/hw/xfree86/common/xf86Xinput.c:1013
        pInfo = 0x22f5280
        drv = 0x22ff920
        isMaster = 0
#8  0x0000000000429830 in CloseDeviceList (listHead=0x7f22e8) at /var/tmp/portage/x11-base/xorg-server-1.12.2/work/xorg-server-1.12.2/dix/devices.c:964
        freedIds = {0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0 <repeats 26 times>}
        dev = <optimized out>
#9  0x0000000000429db2 in CloseDownDevices () at /var/tmp/portage/x11-base/xorg-server-1.12.2/work/xorg-server-1.12.2/dix/devices.c:993
        dev = 0x0
#10 0x00000000004230fc in main (argc=10, argv=0x7fff041a4108, envp=<optimized out>)
    at /var/tmp/portage/x11-base/xorg-server-1.12.2/work/xorg-server-1.12.2/dix/main.c:321
        i = <optimized out>
        alwaysCheckForInput = {0, 1}