Gem::Ext::BuildError: ERROR: Failed to build gem native extension. - CentOS 6.5

Question

I'm trying to get Ruby version 2.0.0-p353 to run on Nginx 1.4.7 on CentOS 6.5. Everything installs as expected, but when I get to the point of running bundle install I get the following error:

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

/usr/local/rvm/rubies/ruby-2.0.0-p353/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.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/usr/local/rvm/rubies/ruby-2.0.0-p353/bin/ruby
        --with-pg
        --without-pg
        --with-pg-config
        --without-pg-config
        --with-pg_config
        --without-pg_config
        --with-pg-dir
        --without-pg-dir
        --with-pg-include
        --without-pg-include=${pg-dir}/include
        --with-pg-lib
        --without-pg-lib=${pg-dir}/

extconf failed, exit code 1

Gem files will remain installed in /root/.rvm/gems/ruby-2.0.0-p353@rails4/gems/pg-0.17.1 for inspection.
Results logged to /root/.rvm/gems/ruby-2.0.0-p353@rails4/extensions/x86_64-linux/2.0.0/pg-0.17.1/gem_make.out
An error occurred while installing pg (0.17.1), and Bundler cannot continue.
Make sure that `gem install pg -v '0.17.1'` succeeds before bundling.

I couldn't locate the mkmf.log file mentioned.

Solution

checking for libpq-fe.h... no

You need the Postgresql development libraries.

Try:

yum install postgresql-devel

or whatever is specific to your OS.