[Ruby on Rails] bundle install fails "An error occurred while installing pg (1.2.3), and Bundler cannot continue."

error contents

I got the following error when I did bundle install.

An error occurred while installing pg (1.2.3), and Bundler cannot continue.
Make sure that `gem install pg -v '1.2.3' --source 'https://rubygems.org/'` succeeds before bundling.

As told

gem install pg -v '1.2.3' --source 'https://rubygems.org/'

I did, but the error doesn't go away ...

environment

ruby : 2.6.3p62 (2019-04-16 revision 67580) [universal.x86_64-darwin19] Rails : 6.0.3.4

solution

brew install postgresql

It seems that postgresql needs to be prepared locally in order to install gem pg. After this, I re-bundle install and it was fixed!