An error occurred while installing pg (0.18.4), and Bundler cannot continue. Make sure that `gem install pg -v '0.18.4' --source 'https://rubygems.org/'` succeeds before bundling.
As a ruby on rails developer, you must be seen the above error at least once.
How to fix the issue?
gem install pg -v '0.18.4' -- --with-cflags="-Wno-error=implicit-function-declaration"