Comment 49 for bug 1301839

Hm. This seems to be it:

X: ../include/privates.h:122: dixGetPrivateAddr: Assertion `key->initialized' failed.

X.Org X Server 1.15.1
Release Date: 2014-04-13
X Protocol Version 11, Revision 0
Build Operating System: Linux 3.14.0-4-ARCH x86_64
Current Operating System: Linux c-l 3.15.0-1-mainline #1 SMP PREEMPT Mon Apr 21 01:47:32 CEST 2014 x86_64
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-linux-mainline root=UUID=650b9f2f-d077-48e9-9fc2-7b6f2294599a rw
Build Date: 14 April 2014 08:39:09AM

Current version of pixman: 0.32.4
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.1.log", Time: Thu Apr 24 09:43:42 2014
(==) Using config directory: "/etc/X11/xorg.conf.d"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
Initializing built-in extension Generic Event Extension
Initializing built-in extension SHAPE
Initializing built-in extension MIT-SHM
Initializing built-in extension XInputExtension
Initializing built-in extension XTEST
Initializing built-in extension BIG-REQUESTS
Initializing built-in extension SYNC
Initializing built-in extension XKEYBOARD
Initializing built-in extension XC-MISC
Initializing built-in extension SECURITY
Initializing built-in extension XINERAMA
Initializing built-in extension XFIXES
Initializing built-in extension RENDER
Initializing built-in extension RANDR
Initializing built-in extension COMPOSITE
Initializing built-in extension DAMAGE
Initializing built-in extension MIT-SCREEN-SAVER
Initializing built-in extension DOUBLE-BUFFER
Initializing built-in extension RECORD
Initializing built-in extension DPMS
Initializing built-in extension Present
Initializing built-in extension DRI3
Initializing built-in extension X-Resource
Initializing built-in extension XVideo
Initializing built-in extension XVideo-MotionCompensation
Initializing built-in extension XFree86-VidModeExtension
Initializing built-in extension XFree86-DGA
Initializing built-in extension XFree86-DRI
Initializing built-in extension DRI2
Loading extension GLX
(II) [KMS] Kernel modesetting enabled.
The XKEYBOARD keymap compiler (xkbcomp) reports:
> Warning: Type "ONE_LEVEL" has 1 levels, but <RALT> has 2 symbols
> Ignoring extra symbols
Errors from xkbcomp are not fatal to the X server
X: ../include/privates.h:122: dixGetPrivateAddr: Assertion `key->initialized' failed.
xterm: fatal IO error 11 (Die Ressource ist zur Zeit nicht verf├╝gbar) or KillClient on X server ":1"
xinit: connection to X server lost