I updated X11 by installing the most recent XQuartz package, 2.7.9. Now, when opening an application that is supported by X11 (e.g., emacs), my terminal throws an error (while X11 starts in the background):
[lap0988:~] user% emacs test.txt &  14071 [lap0988:~] user% Error: Couldn't find per display information
Needless to say, the application doesn't open. My hunch is that this has to do with the DISPLAY environment variable.
[lap0988:~] user% echo $DISPLAY /private/tmp/com.apple.launchd.p7v5k8pNT7/org.macosforge.xquartz:0
Has anyone come across the problem? Can you suggest a straightforward fix for this?