Cannot install pg gem in Mavericks with Postgres.app

Question

I am trying to install the pg gem for use with Postgres.app on my local machine. I am running Mavericks.

Postgres.app is installed and running fine, but I cannot get

Answer 1

For future reference, since a lot of us are posting new paths for the new version numbers:

Currently I'm seeing a symlink called latest in /Applications/Postgres.app/Contents/Versions/.

You should be able to just do:

$ gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/latest/bin/pg_config

And forget about the version number. This might not apply to every (older) version, but I myself was looking for a snippet I could save and reuse.