At the last rails meetup I brought up a question about making rails + postgresql + postGIS + rspec work.
It turns out that if you are using the pg gem, it supports template: option in database.yml.
I wish this was better documented.
It's completely obvious now that I figured it out, but I figured it doesn't hurt to post the answer.
If you ever run into a situation where postgres is missing datatypes like geometry in my case, this is very likely the answer.
I kind of wish that the pg gem would auto generate the template option in database.yml on a new rails project so that would explicitly know which template (if more than one exist for a user) you are using.
The specific error message I was getting was: PG::Error: ERROR: relation "geometry_columns" does not exist.
None of the current stackover flow answers that key on that error mention setting the template flag.