Installing FX/Ruby on Mac OS X

I’m currently teaching myself Ruby and recently needed to install the FXRuby graphical toolkit. I was initially expecting this to be as simple as

sudo gem install fxruby

However running this command on my Mac OS X 10.8 machine returned the following error output

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

        /Users/dchetwyn/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb
*** 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/dchetwyn/.rvm/rubies/ruby-1.9.3-p194/bin/ruby
	--with-fox-dir
	--without-fox-dir
	--with-fox-include
	--without-fox-include=${fox-dir}/include
	--with-fox-lib
	--without-fox-lib=${fox-dir}/lib
	--with-fxscintilla-dir
	--without-fxscintilla-dir
	--with-fxscintilla-include
	--without-fxscintilla-include=${fxscintilla-dir}/include
	--with-fxscintilla-lib
	--without-fxscintilla-lib=${fxscintilla-dir}/lib
extconf.rb:31:in `find_installed_fox_version': couldn't find FOX header files (RuntimeError)
	from extconf.rb:134:in `'

Gem files will remain installed in /Users/dchetwyn/.rvm/gems/ruby-1.9.3-p194/gems/fxruby-1.6.25 for inspection.
Results logged to /Users/dchetwyn/.rvm/gems/ruby-1.9.3-p194/gems/fxruby-1.6.25/ext/fox16/gem_make.out

Although this error message is a little ambiguous, investigation revealed that the error was occurring because the FOX toolkit was not installed on my machine. FXRuby is a Ruby interface to the FOX graphical toolkit, so therefore requires FOX to be installed on the machine first. I already had the Homebrew package manager installed, so installing FOX was as simple as

brew install fox

Running sudo gem install fxruby a second time then successfully installed FXRuby.