解决 gem install rmagick error

gem install rmagick -v '2.13.1'
Building native extensions.  This could take a while...
ERROR:  Error installing rmagick:
	ERROR: Failed to build gem native extension.

        /home/jiahe/.rvm/rubies/ree-1.8.7-2011.03/bin/ruby extconf.rb
checking for Ruby version >= 1.8.5... yes
checking for gcc... yes
checking for Magick-config... no
Can't install RMagick 2.13.1. Can't find Magick-config in /home/jiahe/.rvm/gems/ree-1.8.7-2011.03/bin:/home/jiahe/.rvm/gems/ree-1.8.7-2011.03@global/bin:/home/jiahe/.rvm/rubies/ree-1.8.7-2011.03/bin:/home/jiahe/.rvm/gems/ree-1.8.7-2011.03/bin:/home/jiahe/.rvm/gems/ree-1.8.7-2011.03@global/bin:/home/jiahe/.rvm/rubies/ree-1.8.7-2011.03/bin:/home/jiahe/.rvm/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/home/jiahe/.rvm/rubies/ree-1.8.7-2011.03/bin/ruby

sudo apt-get install imagemagick libmagickwand-dev