Gem Install PG mysterious error extconf.rb related - ruby-on-rails-3

Question

I am trying to update my pg gem and I am getting the following error
Building native extensions. This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
/Users/larson/.rvm/rubies/ruby-1.9.2-p290/bin/ruby extconf.rb --with-pg-config=/Library/PostgreSQL/9.1/bin/pg_config
Using config values from /Library/PostgreSQL/9.1/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
--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=/Users/larson/.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
/Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:368:in `try_do': The complier failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:452:in `try_cpp'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:853:in `block in find_header'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:693:in `block in checking_for'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:280:in `block (2 levels) in postpone'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:280:in `block in postpone'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:276:in `postpone'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:692:in `checking_for'
from /Users/larson/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:852:in `find_header'
from extconf.rb:40:in `<main>'
Gem files will remain installed in /Users/larson/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.13.2 for inspection.
Results logged to /Users/larson/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.13.2/ext/gem_make.out
I tried searching for the mkmf.log file and couldn't find it. I tried a couple of approaches, including putting the directory of the pg_conf file but nothing has worked so far. I am trying this on 10.6.8. snow leopard and my ruby is 1.9.2-p290. I have pg 9.1 installed.
I tried this:
gem install pg
gem install pg -- --with-pg-config=/usr/local/bin/pg_config
This issue appeared after I replaced my macbook pro hard drive and restored the system via time machine. Should I reinstall XCode? Any other suggestions?

Answer 1

I had a similar problem. I got round it by updating rvm:
rvm get latest
rvm reload
rvm --force install 1.9.2