I got to error installing pg gem - ruby-on-rails

Question

I'm on Ubuntu 10.04, how to fix this error?
When I use bundle install command, this install the necessary gems for run the app with rails s.
But "bundle install" command fails too.
I don´t understand the console prompt, can somebody help me?
antonio#antonio-desktop:~/Descargas/ecozap$ gem install pg -v 0.15.1
Building native extensions. This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
/usr/local/rvm/rubies/ruby-1.9.3-p484/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-1.9.3-p484/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
extconf failed, exit code 1
Gem files will remain installed in /usr/local/rvm/gems/ruby-1.9.3-p484/gems/pg-0.15.1 for inspection.
Results logged to /usr/local/rvm/gems/ruby-1.9.3-p484/extensions/x86-linux/1.9.1/pg-0.15.1/gem_make.out
When I used the sudo apt-get install libpq-dev, I´m getting the following error:
antonio # antonio-desktop: ~ / Downloads / ECOZAP $ sudo apt-get install libpq-dev
[sudo] password for antonio:
E: Failed to lock / var / lib / dpkg / lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/ var / lib / dpkg /), maybe there is another process using it?

Answer 1

All you have to do is close any other package manager that is locking apt and install libpq-dev again.