Xfce 4.12.0 won't start

[Ricardo Wurmus]

Hi Guix,

I just upgraded my GuixSD test machine with "guix pull && guix package
-u".  One of the upgrades was Xfce 4.10 -> 4.12.

After rebooting Xfce no longer starts.  My ~/.xsession script only runs
"exec startxfce4".  I noticed that the startxfce4 script is provided by
both "xfce" and "xfce-session".

startxfce4 fails with this error:

  /gnu/store/...-xfce4-session-4.12.0/bin/startxfce4: line 118: exec: xinit: 
not found

After installing the "xinit" package I get this error on running
"startxfce4":

  xinit: error while loading shared libraries: 
/gnu/store/...-libxdmcp-1.1.1/lib/libXdmcp.so.6: file too short.

Has anyone else run into issues like this?

~~ Ricardo