unable to install pg gem - *** extconf.rb failed ***

gem install pg

(Operating system is Fedora 2.6.40.6-0.fc15.i686)
Hi there quiet recently I had a big problem with this guy - gem install pg

It threw me :

$ gem install pg
Building native extensions.  This could take a while...
ERROR:  Error installing pg:
	ERROR: Failed to build gem native extension.

        /home/andrej/.rvm/rubies/ruby-1.9.2-p290/bin/ruby extconf.rb
checking for pg_config... yes
Using config values from /usr/bin/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=/home/andrej/.rvm/rubies/ruby-1.9.2-p290/bin/ruby
	--with-pg
	--without-pg
	--with-pg-dir
	--without-pg-dir
	--with-pg-include
	--without-pg-include=${pg-dir}/include
	--with-pg-lib
	--without-pg-lib=${pg-dir}/lib
	--with-pg-config
	--without-pg-config
	--with-pg_config
	--without-pg_config


Gem files will remain installed in /home/andrej/.rvm/gems/ruby-1.9.2-p290@c/gems/pg-0.11.0 for inspection.
Results logged to /home/andrej/.rvm/gems/ruby-1.9.2-p290@c/gems/pg-0.11.0/ext/gem_make.out

and I was kind of unable to find it, but now i got it:

AND THE MAGIC TRICK :

is that you do not have this installed  -- >  postgres-devel

so go get it :

sudo yum install postgresql-devel

Thats all... than just gem install pg and there it goes :D such a silly mistake :D

It helped me too. Thanks!