Attempting local installation of 'rmagick'
Local gem file not found: rmagick*.gem
Attempting remote installation of 'rmagick'
Building native extensions.  This could take a while...
configure: error: Can't install RMagick. Can't find Magick-config or GraphicsMagick-config program.
ERROR:  While executing gem ... (RuntimeError)
    ERROR: Failed to build gem native extension.
Gem files will remain installed in /var/lib/gems/1.8/gems/rmagick-1.13.0 for inspection.
  ruby gem_extconf.rb install rmagick\n
sh configure

Configuring RMagick 1.13.0
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ANSI C... none needed
checking for ruby... /usr/bin/ruby
checking for Magick-config... no
checking for GraphicsMagick-config... no
RMagick configuration failed with status 1.