==> Validating source files with md5sums...
ruby-gnome2-all-0.90.2.tar.gz ... Passed
==> Extracting Sources...
-> Extracting ruby-gnome2-all-0.90.2.tar.gz with bsdtar
==> Starting build()...
extconf.rb: Entering directory `libglade'
/usr/lib/ruby/1.9.1/rubygems.rb:762:in `report_activate_error': Could not find RubyGem pkg-config (>= 0) (Gem::LoadError)
from /usr/lib/ruby/1.9.1/rubygems.rb:219:in `activate'
from /usr/lib/ruby/1.9.1/rubygems.rb:1065:in `gem'
from /tmp/yaourt-tmp-ptchinster/aur-ruby-libglade/src/ruby-gnome2-all-0.90.2/glib2/lib/mkmf-gnome2.rb:17:in `rescue in <top (required)>'
from /tmp/yaourt-tmp-ptchinster/aur-ruby-libglade/src/ruby-gnome2-all-0.90.2/glib2/lib/mkmf-gnome2.rb:13:in `<top (required)>'
from <internal:lib/rubygems/custom_require>:29:in `require'
from <internal:lib/rubygems/custom_require>:29:in `require'
from /tmp/yaourt-tmp-ptchinster/aur-ruby-libglade/src/ruby-gnome2-all-0.90.2/libglade/extconf.rb:25:in `<main>'
extconf.rb: Leaving directory 'libglade'
-----
Ignored libraries: libglade
-----
Done.
-----
SUCCEEDED: NONE
FAILED: NONE
-----
Done.
==> Build failed, perhaps you have to run "gem install pkg-config" as root.
Aborting...
==> ERROR: Makepkg was unable to build ruby-libglade.
==> Restart building ruby-libglade ? [y/N]
==> --------------------------------------
==>