Building native extensions. This could take a while... ERROR: While executing gem ... (Gem::Installer::ExtensionBuildError) ERROR: Failed to build gem native extension. ruby extconf.rb install ruby-debug-ide --no-rdoc --no-ri --include-dependencies --version > 0 nmake 'nmake' is not recognized as an internal or external command, operable program or batch file. Gem files will remain installed in C:/InstantRails-1.2.6/ruby/lib/ruby/gems/1.8/gems/ruby-debug-base-0.10.0 for inspection. Results logged to C:/InstantRails-1.2.6/ruby/lib/ruby/gems/1.8/gems/ruby-debug-base-0.10.0/ext/gem_make.out