Installing pg gem with bundler on Mac M1

If you’re lucky / unlucky (whichever applies to you) to own M1 powered Macbook, you may encounter errors when installing pg gem using bundle install command for your Ruby application.

The fix them, you need to obtain libpq from Homebrew and configure bundler to use pg_config from there.

If you followed setup for running multiple Postgres versions on Mac OS, you might already have pg_config in your $PATH. Unfortunately, it’s not compatible with pg gem and libpq from Homebrew must be used.

The full solution strips down into 2 commands:

  1. bundle install libpq
  2. bundle config set --global --with-pg-config=/opt/homebrew/opt/libpq/bin/pg_config

Now you can run bundle install and keep developing as usual.