$ xfwm4 --version
	This is xfwm4 version 4.12.3git.e180e80.20151109 (revision e180e80.20151109) for Xfce 4.12
	Released under the terms of the GNU General Public License.
	Compiled against GTK+-2.24.28, using GTK+-2.24.28.

	Build configuration and supported features:
	- Startup notification support:                 Yes
	- XSync support:                                Yes
	- Render support:                               Yes
	- Xrandr support:                               Yes
	- Xpresent support:                             Yes
	- Embedded compositor:                          Yes
	- Epoxy support:                                Yes
	- KDE systray proxy (deprecated):               No


$ dmesg
...
[   32.372030] xfwm4[1631]: segfault at 0 ip 00007f66ad94bbaf sp 00007ffcfb1a4428 error 4 in libc-2.22.90.so[7f66ad8b6000+1be000]

$ coredumpctl gdb
           PID: 1631 (xfwm4)
           UID: 1000 (liveuser)
           GID: 1000 (liveuser)
        Signal: 11 (SEGV)
     Timestamp: Wed 2015-11-25 06:01:38 EST (1min 14s ago)
  Command Line: xfwm4
    Executable: /usr/bin/xfwm4
 Control Group: /user.slice/user-1000.slice/session-1.scope
          Unit: session-1.scope
         Slice: user-1000.slice
       Session: 1
     Owner UID: 1000 (liveuser)
       Boot ID: 470329c95f774500be73eb1804de7a69
    Machine ID: ca5442939a18491dada18afb3c026c61
      Hostname: localhost
      Coredump: /var/lib/systemd/coredump/core.xfwm4.1000.470329c95f774500be73eb1804de7a69.1631.1448449298000000.lz4
       Message: Process 1631 (xfwm4) of user 1000 dumped core.
                
                Stack trace of thread 1631:
                #0  0x00007f66ad94bbaf __rawmemchr (libc.so.6)
                #1  0x00007f66ad932ff2 _IO_str_init_static_internal (libc.so.6)
                #2  0x00007f66ad921c17 __GI___isoc99_vsscanf (libc.so.6)
                #3  0x00007f66ad921bb7 __isoc99_sscanf (libc.so.6)
                #4  0x00007f66b25d5e52 epoxy_glx_version (libepoxy.so.0)
                #5  0x0000565552cbf83d init_glx (xfwm4)
                #6  0x0000565552cb274b initialize (xfwm4)
                #7  0x00007f66ad8d6780 __libc_start_main (libc.so.6)
                #8  0x0000565552cb2829 _start (xfwm4)

GNU gdb (GDB) Fedora 7.10.50.20151113-33.fc24
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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Type "show configuration" for configuration details.
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Reading symbols from /usr/bin/xfwm4...Reading symbols from /usr/lib/debug/usr/bin/xfwm4.debug...done.
done.
[New LWP 1631]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `xfwm4'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  rawmemchr () at ../sysdeps/x86_64/rawmemchr.S:37
37		movdqu	(%rdi), %xmm0
Missing separate debuginfos, use: dnf debuginfo-install adwaita-gtk2-theme-3.18.0-1.fc24.x86_64 bzip2-libs-1.0.6-17.fc24.x86_64 libgcc-5.2.1-5.fc24.x86_64
(gdb) backtrace full
#0  rawmemchr () at ../sysdeps/x86_64/rawmemchr.S:37
No locals.
#1  0x00007f66ad932ff2 in _IO_str_init_static_internal (
    sf=sf@entry=0x7ffcfb1a4460, ptr=ptr@entry=0x0, size=size@entry=0, 
    pstart=pstart@entry=0x0) at strops.c:41
        fp = 0x7ffcfb1a4460
        end = <optimized out>
#2  0x00007f66ad921c17 in __GI___isoc99_vsscanf (string=0x0, 
    format=0x7f66b25f3432 "%d.%d", args=args@entry=0x7ffcfb1a4588)
    at isoc99_vsscanf.c:41
        ret = -1379440736
        sf = {_sbf = {_f = {_flags = -72515584, _IO_read_ptr = 0x0, 
              _IO_read_end = 0x0, _IO_read_base = 0x0, _IO_write_base = 0x0, 
              _IO_write_ptr = 0x0, _IO_write_end = 0x0, _IO_buf_base = 0x0, 
              _IO_buf_end = 0x0, _IO_save_base = 0x0, _IO_backup_base = 0x0, 
              _IO_save_end = 0x0, _markers = 0x0, _chain = 0x0, 
              _fileno = -82164376, _flags2 = 0, _old_offset = 140724521289060, 
              _cur_column = 0, _vtable_offset = 120 'x', _shortbuf = "S", 
              _lock = 0x0, _offset = 1275133953, _codecvt = 0x0, 
              _wide_data = 0xffffffffffffffff, _freeres_list = 0x0, 
              _freeres_buf = 0x565553785c00, __pad5 = 94924473365264, 
              _mode = -1, 
              _unused2 = "UV\000\000\000\\xSUV\000\000\030F\032\373\374\177\000"---Type <return> to continue, or q <return> to quit---
}, vtable = 0x7f66adc767a0 <_IO_str_jumps>}, _s = {_allocate_buffer = 0x25, 
            _free_buffer = 0x7f66ad939b4c <__GI___libc_free+76>}}
#3  0x00007f66ad921bb7 in __isoc99_sscanf (s=<optimized out>, 
    format=format@entry=0x7f66b25f3432 "%d.%d") at isoc99_sscanf.c:31
        arg = {{gp_offset = 16, fp_offset = 48, 
            overflow_arg_area = 0x7ffcfb1a4660, 
            reg_save_area = 0x7ffcfb1a45a0}}
        done = -1379440736
#4  0x00007f66b25d5e52 in epoxy_glx_version (dpy=0x565553785c00, 
    screen=screen@entry=0) at dispatch_glx.c:60
        server_major = 1401905289
        server_minor = 22101
        client_major = 1401027376
        client_minor = 22101
        server = <optimized out>
        client = <optimized out>
        version_string = <optimized out>
        ret = <optimized out>
        __PRETTY_FUNCTION__ = "epoxy_glx_version"
#5  0x0000565552cbf83d in init_glx (screen_info=0x56555381fb30)
    at compositor.c:1316
        version = <optimized out>
#6  compositorManageScreen (screen_info=0x56555381fb30) at compositor.c:4342
---Type <return> to continue, or q <return> to quit---
        buffer = 2
        display_info = 0x56555381cea0
        pa = {repeat = 0, alpha_map = 140078975523660, alpha_x_origin = 2, 
          alpha_y_origin = 0, clip_x_origin = 1401015968, 
          clip_y_origin = 22101, clip_mask = 1, graphics_exposures = 0, 
          subwindow_mode = 1, poly_edge = 0, poly_mode = 0, 
          dither = 94924473240968, component_alpha = 2}
        visual_format = <optimized out>
        screen_info = 0x56555381fb30
#7  0x0000565552cb274b in initialize (replace_wm=0, 
    compositor_mode=<optimized out>) at main.c:543
        xfwm4_compositor = 1
        screen_info = 0x56555381fb30
        gscr = <optimized out>
        i = 0
        nscreens = 1
#8  main (argc=1, argv=0x7ffcfb1a4a18) at main.c:667
        version = 0
        replace_wm = 0
        context = <optimized out>
        error = 0x0
        option_entries = {{long_name = 0x565552cf0c91 "daemon", 
            short_name = 0 '\000', flags = 8, arg = G_OPTION_ARG_CALLBACK, 
---Type <return> to continue, or q <return> to quit---
            arg_data = 0x565552cce420 <daemon_callback>, 
            description = 0x565552cf08c0 "Fork to the background (not supported)", arg_description = 0x0}, {long_name = 0x565552cf0c98 "compositor", 
            short_name = 0 '\000', flags = 0, arg = G_OPTION_ARG_CALLBACK, 
            arg_data = 0x565552cce450 <compositor_callback>, 
            description = 0x565552cf0ca3 "Set the compositor mode", 
            arg_description = 0x565552cf0cbb "on|off|auto"}, {
            long_name = 0x565552cf0cc7 "replace", short_name = 0 '\000', 
            flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x7ffcfb1a47f4, 
            description = 0x565552cf08e8 "Replace the existing window manager", arg_description = 0x0}, {long_name = 0x565552cf0ccf "version", 
            short_name = 86 'V', flags = 0, arg = G_OPTION_ARG_NONE, 
            arg_data = 0x7ffcfb1a47f0, 
            description = 0x565552cf0910 "Print version information and exit", 
            arg_description = 0x0}, {long_name = 0x0, short_name = 0 '\000', 
            flags = 0, arg = G_OPTION_ARG_NONE, arg_data = 0x0, 
            description = 0x0, arg_description = 0x0}}
(gdb) quit