An error occurred while installing pg (0.17.1), and Bundler cannot continue

Question

I just installed Rails 4.0.2 and when creating a new app, in the bundle stage I get:

Installing pg (0.17.1) 
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
/Users/Dee/.rvm/rubies/ruby-2.0.0-p247/bin/ruby extconf.rb 
checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
--with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

How do I fix this?

Answer 1

Some kind of error resported here Installing PG gem on OS X - failure to build native extension

To install dependencies on Ubuntu try this:

sudo apt-get install libpq-dev

and this

gem install pg

Answer 2

I'm on a Mac running Mavericks. My solution was to install Postgres.

And then in terminal install using homebrew with the configuration:

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

Note: This answer has been edited to use the latest symlink that is currently included in shipping versions of the Postgres app.

Previous versions suggested:

gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config

Answer 3

app root:

1. brew update
2. brew install postgres
3. gem install pg -- --with-pg-config=/usr/local/Cellar/postgresql/9.3.4/bin/pg_config
4. bundle install
5. ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents
6. launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
7. createuser -s -r postgres
8. rake db:create:all
9. rake db:migrate
10. rails s

NOTE: replace the version number in step 3 if needed.

Answer 4

Previously working answer with older version

I installed under mac OSX Mavericks, having the postgres app (Version 9.2.2.0 ) from www.postgresapp.com installed. The underlying problem was simpy that the since postgres was installed via the app, the configuration file resides on a location which is not the default one when installing it without postgressapp. so we need to tell gem where to find this file by:

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

Hope it helps