gistfile1.sh

FYI: If you come from Google on this one... YAML is installed with Ruby... If it can be compiled! When installing 1.9.2 with "rvm install 1.9.2" 
I stumbled upon Yaml not installing because gcc4.2 wasn't on my system. Turned out it was because Xcode 4.2 doesn't deliver GCC 4.2 anymore so 
you'll have to either Install Xcode 4.1 (or at least the Unix tools) or install gcc by hand (or brew, or anything).


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

  /Users/mc/.rvm/rubies/ruby-1.9.2-p0/bin/ruby extconf.rb
  checking for yaml.h... no
  yaml.h is missing. Try 'port install libyaml +universal' or 'yum install libyaml-devel'
  *** 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/mc/.rvm/rubies/ruby-1.9.2-p0/bin/ruby
    --with-libyaml-dir
    --without-libyaml-dir
    --with-libyaml-include
    --without-libyaml-include=${libyaml-dir}/include
    --with-libyaml-lib
    --without-libyaml-lib=${libyaml-dir}/lib


  Gem files will remain installed in /Users/mc/.rvm/gems/ruby-1.9.2-p0/gems/psych-1.2.2 for inspection.
  Results logged to /Users/mc/.rvm/gems/ruby-1.9.2-p0/gems/psych-1.2.2/ext/psych/gem_make.out