XQuartz startup very slow I use Xquartz.app (latest stable version, 2.77) fairly regularly. In Yosemite (fresh install) I've noticed that it takes a long time to start up (I've got a SSD so it shouldn't take so long to launch).

Here's the relevant part of my Console:

30.10.14 17:51:05,527 com.apple.xpc.launchd[1]: (org.macosforge.xquartz.privileged_startx[2371]) Endpoint has been activated through legacy launch(3) APIs. Please switch to XPC or bootstrap_check_in(): org.macosforge.xquartz.privileged_startx
30.10.14 17:51:05,593 org.macosforge.xquartz.privileged_startx[2371]: lockfile: Sorry, giving up on "/opt/X11/var/run/font_cache.lock"
30.10.14 17:51:05,594 org.macosforge.xquartz.privileged_startx[2371]: font_cache is already running.
30.10.14 17:51:05,594 org.macosforge.xquartz.privileged_startx[2371]: If you believe this to be erroneous, please remove /opt/X11/var/run/font_cache.lock.
30.10.14 17:51:05,752 org.macosforge.xquartz.startx[2363]: xauth:  file /Users/lucas/.serverauth.2364 does not exist
30.10.14 17:51:17,821 org.macosforge.xquartz.startx[2363]: /opt/X11/bin/xinit: XFree86_VT property unexpectedly has 0 items instead of 1


Does anyone know what the problem might be / how I can fix it?

Thanks!
Some software creates lock files to indicate to other pieces of software that a resource is being used. In theory they will delete the lock file once they are done using the resource. However if they crash they can end up leaving the lock file behind.

This is what is happening here. XQuartz is launching and wants to update the font cache but it sees the font_cache.lock file so thinks the font cache is already being updated. Most likely it isn't and it just crashed the last time it ran, leaving the lock file behind.

Just delete the /opt/X11/var/run/font_cache.lock file and try XQuartz again.