nexace

nexace@viking:~/yaba/RSYaba$ sudo gem install hpricot
Building native extensions.  This could take a while...
ERROR:  Error installing hpricot:
	ERROR: Failed to build gem native extension.

        /usr/bin/ruby1.9.1 extconf.rb
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError)
	from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
	from extconf.rb:1:in `<main>'


Gem files will remain installed in /var/lib/gems/1.9.1/gems/hpricot-0.8.6 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/hpricot-0.8.6/ext/fast_xs/gem_make.out