From: "Ben W." Date: 2012-04-03T13:58:00+09:00 Subject: Problem Installing Rails on Ruby 1.9.3 I am trying to install rails on Ruby 1.9.3. When I execute the command: $ sudo gem install rails I receive the error below. How do I resolve this? Building native extensions. This could take a while... ERROR: Error installing rails: ERROR: Failed to build gem native extension. /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/json-1.6.6 for inspection. Results logged to /Library/Ruby/Gems/1.8/gems/json-1.6.6/ext/json/ext/generator/gem_make.out Benjamins-MacBook-Air:~ benrweiss$ sudo gem install rails Password: Building native extensions. This could take a while... ERROR: Error installing rails: ERROR: Failed to build gem native extension. /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/json-1.6.6 for inspection. Results logged to /Library/Ruby/Gems/1.8/gems/json-1.6.6/ext/json/ext/generator/gem_make.out -- Posted via http://www.ruby-forum.com/.