PostgreSQL's pg gem won't install on OS X - ruby-on-rails

Question

I've looked all the solutions in the internet for this, reinstalled everything and still nothing... When i do gem install pg i get:
Building native extensions. This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
/Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb --with-pgsql->lib=/usr/local/Cellar/postgresql/9.2.1/lib --with-pg->config=/usr/local/Cellar/postgresql/9.2.1/bin/pg_config
Using config values from /usr/local/Cellar/postgresql/9.2.1/bin/pg_config
checking for libpq-fe.h... * 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=/Users/henriquedubugras/.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
/Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:381:in try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:506:intry_cpp'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:970:in block in find_header'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:790:inblock in checking_for'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:284:in block (2 levels) in postpone'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:254:inopen'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:284:in block in postpone'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:254:inopen'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:280:in postpone'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:789:inchecking_for'
from /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:969:in find_header'
from extconf.rb:41:in'
Gem files will remain installed in /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/pg-0.14.1 for inspection.
Results logged to /Users/henriquedubugras/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/pg-0.14.1/ext/gem_make.out
I tried setting the pg_config path, my xcode is installed, my command line tools from xcode is installed, my ruby version is 1.9.3 installed by RVM.
My mac is OS X Mountain Lion
Thanks guys!

Answer 1

You're missing the Postgres client library header files (libpq-fe.h). In Debian the package is called libpq-dev. I don't know Mac packaging at all, but if there's no Mac respository building the PG client libs from source would work.

Answer 2

i would recommend installing rvm https://rvm.io/rvm/install
then run rvm requirements. this will install all required packages, you're probably missing "gcc49" after this install rails and yore good to install postgres. i would suggest postgresapp or postgresql.