With the exception of the Scent rage power ("KEY:Scent ~ Rage"), all of the rage powers in the Core Rulebook set (pfcr_abilities_class.lst) lack a KEY, but all the rage powers in the UC set (pfuc_abilities_archetypes.lst) use the KEY format "<name> ~ Rage Power", and all references to rage powers from the Core Rulebook as prerequisites assume this same format (e.g. "Ghost Rager ~ Rage Power" has a prerequisite of "Superstition ~ Rage Power", but the actual ability in Core is just "Superstition"). This makes it impossible to select many of the Ultimate Combat rage powers. Adding "KEY:<name> ~ Rage Power" to all the Core Rulebook rage powers so that they're consistent with the UC set would fix the problem.
I grepped for existing references to the Core Rulebook rage powers outside the UC set which would need to be updated as well:
pfb2_kits_races_jkl.lst:Lycanthrope (Wereboar/Human Form)
pfapg_equip_wondrousitems.lst:Torc of Lionheart Fury
Moment of Clarity
Scent ~ Rage
Completed: At revision: 20007 to 20013
6.0 Branch - Completed: At revision: 20015