I've got a headless machine with tigervnc installed. The new version of tigervnc seems to require xsm in order to fire properly. by stracing the vncsession binary, I was able to discover it was trying to launch xsm...and failing because it wasn't there. To reproduce: emerge -C xsm emerge tigervnc # observe xsm isn't installed ...then configure and attempt to start /etc/init.d/tigervnc
nevermind...I added... exec startxfce4 ...to /etc/X11/xinit/Xclients and everything is hunky-dory...i.e. it doesn't fail-back to xsm anymore.