Вот на чём остановился, не подскажите в чём дело?

root@alexey-laptop:/usr/bin# gem install mongrel BlueCloth RedCloth sqlite3-ruby ZenTest
Building native extensions. This could take a while...
Building native extensions. This could take a while...
Successfully installed gem_plugin-0.2.3
Successfully installed daemons-1.0.10
Successfully installed fastthread-1.0.1
Successfully installed cgi_multipart_eof_fix-2.5.0
Successfully installed mongrel-1.1.5
Successfully installed BlueCloth-1.0.0
Building native extensions. This could take a while...
Successfully installed RedCloth-4.1.1
Building native extensions. This could take a while...
ERROR: Error installing sqlite3-ruby:
ERROR: Failed to build gem native extension.

/usr/bin/ruby1.8 extconf.rb install mongrel BlueCloth RedCloth sqlite3-ruby ZenTest
checking for fdatasync() in -lrt... yes
checking for sqlite3.h... no

make
make: *** Нет правила для сборки цели `ruby.h', требуемой для `sqlite3_api_wrap.o'. Останов.

Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.2.4 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.2.4/ext/sqlite3_api/gem_make.out
ERROR: While executing gem ... (Gem::RemoteFetcher::FetchError)
bad response Internal Server Error 500 (http://rubyforge.iasi.roedu.net/gems/ZenTest-3.11...