Today I Learned

Installing the pg gem with the Postgres app

Everytime I need to install the pg gem to use Postgres with Rails I see the following error, and everytime I forget the solution.

An error occurred while installing pg (1.1.3), and Bundler cannot continue.
Make sure that gem install pg -v '1.1.3' --source 'https://rubygems.org/' succeeds before bundling.

Well, hey there, future self. Nice to see you. I think this is what you’re looking for.

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