The pg gem was pinned in #12219 as tests failed on our Jenkins slaves under Ruby 2.2 or higher due to the pg build process which was preferring /usr/lib64/libruby* from the base OS's old Ruby over the RVM Ruby.

ruby-devel has been uninstalled on all of our Jenkins slaves now, so pg should be unpinned so we have the latest version with other fixes.

The build process bug is still unfixed and may not be corrected unless there's a behaviour change in Ruby's build process, but the workaround to remove ruby-devel when using RVM is straightforward.