Fix Non-Working PG Gem on Dev (Ubuntu).txt

After upgrading from Ruby 1.9.2 to 1.9.3 on a test server, the pg would not install.

   mv ~/.rvm/usr/lib ~/.rvm/usr/lib_rvm 
   bundle config build.pg --with-pg-config=/usr/bin/pg_config.libpq-dev
   gem install pg


The mv line was the breakthrough, see:
http://stackoverflow.com/questions/8814924/gem-install-pg-can-not-bind-to-libpq

---

which pg_config

---

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

        /home/scriptive/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb
checking for pg_config... yes
Using config values from /usr/bin/pg_config
checking for libpq-fe.h... yes
checking for libpq/libpq-fs.h... yes
checking for pg_config_manual.h... yes
checking for PQconnectdb() in -lpq... no
checking for PQconnectdb() in -llibpq... no
checking for PQconnectdb() in -lms/libpq... no
Can't find the PostgreSQL client library (libpq)
*** 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
     --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/scriptive/.rvm/rubies/ruby-1.9.3-p194/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
     --with-pqlib
     --without-pqlib
     --with-libpqlib
     --without-libpqlib
     --with-ms/libpqlib
     --without-ms/libpqlib