title: Rails + Postgres migration - why am I receiving the error "PG::UndefinedFunction: ERROR: function gen_random_uuid() does not exist"?
body: <p>One of my Rails migrations uses a uuid as the primary key. The Postgres extension <code>gen_random_uuid()</code> should solve this issue, but I continue to get the error after installing the relevant extension (<code>uuid-ossp</code>).</p>