pgRouting/pgrouting — pull request #281 by titanofold (2014-11-18 21:41:03+00:00)
Title: No Contrib When Use Extension

Don't install to ${SHAREDIR}/contrib when USE EXTENSION is true to fit
in with PostgreSQL's directory structure. (pg_routing in the only thing
in ${SHAREDIR}/contrib on 9.1+.)

We're using this on Gentoo and so far I haven't gotten any reports about
this breaking anything.