Am not sure what happened, but after updating deps I lost the ability to open some applications and run others.
Spent more than a day fighting this, turns out xz.tcz was at least part of the problem (exactly how I'm not sure..) glib2 and libxml2 were also updated at the same time, reinstalled xz.tcz to OnBoot and all my apps appear to be functional again.
Apps effected
Firefox
Meld
GnomePlayer
etc