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 sqlite3-ruby
checking for sqlite3.h... no
make
make: *** No rule to make target `ruby.h', needed by `sqlite3_api_wrap.o'. Stop.
Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.2.1 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.2.1/ext/sqlite3_api/gem_make.out