If you encounter errors installing pg gem on an Apple Silicon mac:
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
Then try the below commands firstly; to ensure the homebrew version of libpg is used:
echo 'export PATH="/opt/homebrew/opt/libpq/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc
gem install pg -- --with-pg-config=`which pg_config`
and follow up with bundle install once successful.
This worked for me with the Postgres.app (postgres 14), and having previously installed libpq:
brew install libpq@14.6
