I've been setting up PostgreSQL 9.3 on some CentOS 7 servers and ran
into a problem where the uuid-ossp module wasn't being provided by the
postgresql93-contrib-9.3.5-1PGDG.rhel7.x86_64 package.
Upon investigating it appears that uuid is now disabled by default in
rhel7 builds and I had to rebuild the source RPM with --define 'uuid 1'.
Is there a reason for this change? README.rpm-dist still notes it as
being enabled by default.