Running X11 - 6. Troubleshooting XFree86

6.1 When I launch X11, it quits or crashes almost immediately

First of all: Don't Panic! There are lots of things than can go wrong with X11, and a good number of them can cause startup failures. Further, it is not unusual that X11 crashes when it experiences startup problems. This section tries to provide a comprehensive list of problems you may come across. But first, you need to gather two important pieces of information:

Display server version. You can find the version of the display server in the Finder by clicking once on the X11 or XQuartz icon and then selecting "Get Info" from the menu.

Error messages. These are essential in pinpointing the particular problem you experience. How you get the error messages depends on how you started X11. If you ran startx from a Terminal window, you'll have the messages right there in that window. Remember that you can scroll up. If you started X11 by double-clicking the X11 or XQuartz icon, the messages end up in the system log, which you can access through the Console application in the Utilities folder. Be sure to pick the right set of messages, e.g. the last one.

We'll start with a list of the messages you may see:

_XSERVTransmkdir: Owner of /tmp/.X11-unix should be set to root
_IceTransmkdir: Owner of /tmp/.ICE-unix should be set to root

Class: Harmless. X11 creates hidden directories in /tmp to store the socket "files" for local connections. For security reasons, X11 prefers if these directories are owned by root, but since they are world-writable anyway it will still run without any problems. (Note: It's quite hard to have these dirs owned by root, as Mac OS X wipes out /tmp on reboots and X11 doesn't run with root privileges and doesn't need to.)

cat: /Users/chrisp/.Xauthority: No such file or directory

Class: Mostly harmless. This issue seems to have no impact on operations. You can get rid of them by running touch .Xauthority in your home directory.

Gdk-WARNING **: locale not supported by C library

Class: Harmless. This just means what it says and won't keep the application from working. For more information, see below.

Warning: no access to tty (Inappropriate ioctl for device).
Thus no job control in this shell.

Class: Mostly harmless. X11 launches an interactive shell behind the scenes to run your client startup file (.xinitrc). This was done so that you don't have to add statements to set up PATH in that file. Some shells complain that they're not connected to a real terminal, but that can be ignored since that shell instance is not used for anything that requires job control or the like.

The XKEYBOARD keymap compiler (xkbcomp) reports:
> Error:            Can't find file "unknown" for geometry include
>                   Exiting
>                   Abandoning geometry file "(null)"
Errors from xkbcomp are not fatal to the X server

Class: Mostly harmless. As the message says, it is not fatal. To my knowledge, X11 on Macs doesn't use the XKB extension at all. Probably some client program tries to use it anyway...

startx: Command not found.

Class: Fatal. This can happen when your shell initialization files are not set up to add the X11 executable directory, e.g. /usr/X11/bin, to the PATH variable. Fink is normally set up to do this automatically, so this may indicate that your Fink environment isn't being loaded. Running


in a terminal window, and then starting a new window, will typically resolve this.

_XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
_XSERVTransMakeAllCOTSServerListeners: server already running
Fatal server error:
Cannot establish any listening sockets - Make sure an X server isn't already

Class: Fatal. This can happen when you accidentally run several instances of X11 at once, or maybe after an unclean shutdown (i.e. crash) of X11. It might also be a file permission problem with the sockets for local connections. You can try to clean that up with rm -rf /tmp/.X11-unix. Restarting the computer also helps in most cases (Mac OS X automatically cleans up /tmp when it boots, and the network stack is reset).

Xlib: connection to ":0.0" refused by server
Xlib: Client is not authorized to connect to Server

Class: Fatal. The client programs can't connect to the display server (X11 or XQuartz) because they use bogus authentication data. This can be caused by some VNC installations, by running X11-based apps through sudo, and probably some other freak accidents. The usual fix is to delete the .Xauthority file (which stores the authentication data) in your home directory and re-create an empty file:

rm .Xauthority
touch .Xauthority

Possibly no obvious error:

Class: Fatal. Probably the common cause for X11 startup failures is an incorrect startup file. Typically, a window manager listed in $HOME/.xinitrc or $HOME/.xinitrc.d doesn't get run due to having been uninstalled, or not being in the PATH, or runs in the background rather than the foreground due to having an '&' at the end of its line. In any case, $HOME/.xinitrc reaches its end, xinit interprets this as "the user's session has ended", and kills X11. If the executable cannot be found, there will be an error message to that effect in the terminal window or console log. On the other hand, if the last file has an '&', there will be no error, but X11 will quit. See the sections on .xinitrc.d and the .xinitrc file for more details.

To avoid this, remember to set up the PATH using

. /opt/sw/bin/

in your startup files, and also to end with a long-lived program that is not started in the background, e.g. a window manager or session manager with no '&'. You might also add exec xterm as a fallback for when your window manager or other long-lived item can't be found, e.g. if you remove it.

6.2 "Warning: locale not supported by C library"

These messages are quite common, but harmless. It just means what it says - internationalization is not supported through the standard C library, the program will use the default English messages, date formats, and so on. There are several ways to deal with this:

Next: 7. Usage Tips