title: Postgres issue when upgrading from Rails 4.1.16 to 4.2.0
body: <p>Rails 4.2 AR apparently is dependent on version 0.15 of pg. When I try to build my app with it I get &quot;Failed to build gem native extension.&quot;. Problem lies with &quot;checking for PQconnectionUsedPassword()&quot;. In order to get past this point, I upgraded my installation of Postgres, as it did not support that function. SO I installed the multi-version edition of Postgres, migrated my data to a 10.0 server, and then tried again. Same result. How can I fix this?</p>
  <p>It seems like the native extension builder of the gem installation process is still seeing info from the old Postgres installation (or at least not seeing info from the new installation). How do I get it to see the new one (before you ask, the new one is running and the old one has been stopped? There is a header file that declares PQconnectionUsedPassword in one of the files within my new Postgres app, but I don't know exactly how that process works, so I don't know how to check if we're using the correct folder.</p>