Can't find the 'libpq-fe.h header when trying to install pg gem
pg, postgresql, rails-postgresql, ruby-on-rails, ruby-on-rails-3
Solution
It looks like in Ubuntu that header is part of the `libpq-dev` package (at least in the following Ubuntu versions: 11.04 (Natty Narwhal), 10.04 (Lucid Lynx), 11.10 (Oneiric Ocelot), 12.04 (Precise Pangolin), 14.04 (Trusty Tahr) and 18.04 (Bionic Beaver)):
...
/usr/include/postgresql/libpq-fe.h
...
So try installing `libpq-dev` or its equivalent for your OS:
- For Ubuntu/Debian systems: `sudo apt-get install libpq-dev`
- On Red Hat Linux (RHEL) systems: `yum install postgresql-devel`
- For Mac Homebrew: `brew install postgresql`
- For Mac MacPorts PostgreSQL: `gem install pg -- --with-pg-config=/opt/local/lib/postgresql[version number]/bin/pg_config`
- For OpenSuse: `zypper in postgresql-devel`
- For ArchLinux: `pacman -S postgresql-libs`
Problem
I am using the Ruby on Rails 3.1 pre version. I like to use PostgreSQL, but the problem is installing the `pg` gem. It gives me the following error: ``` $ gem install pg Building native extensions. This could take a while... ERROR: Error installing pg: ERROR: Failed to build gem native extension. /home/u/.rvm/rubies/ruby-1.9.2-p0/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=/home/u/.rvm/rubies/ruby-1.9.2-p0/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/u/.rvm/gems/ruby-1.9.2-p0/gems/pg-0.11.0 for inspection. Results logged to /home/u/.rvm/gems/ruby-1.9.2-p0/gems/pg-0.11.0/ext/gem_make.out ``` How do I solve this problem?