heroku rmagick fail (.gems)

mj:~/work/mm/github/mm mark$ git push origin master
Counting objects: 9, done.
Compressing objects: 100% (7/7), done.
Writing objects: 100% (7/7), 946 bytes, done.
Total 7 (delta 2), reused 0 (delta 0)
To git@github.com:johnsome/mm.git
   07ee404..d2a36a6  master -> master
mj:~/work/mm/github/mm mark$ git push heroku
Counting objects: 12, done.
Compressing objects: 100% (10/10), done.
Writing objects: 100% (10/10), 1.20 KiB, done.
Total 10 (delta 4), reused 0 (delta 0)

-----> Heroku receiving push
-----> Removing .DS_Store files
-----> Rails app detected

-----> Installing gem rmagick from http://rubygems.org
       Building native extensions.  This could take a while...
       ERROR:  Error installing rmagick:
        ERROR: Failed to build gem native extension.
       
       /usr/local/bin/ruby extconf.rb
       checking for Ruby version >= 1.8.5... yes
       checking for gcc... yes
       checking for Magick-config... yes
       checking for ImageMagick version >= 6.4.9... no
       Can't install RMagick 2.13.1. You must have ImageMagick 6.4.9 or later.
       
       *** 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=/usr/local/bin/ruby
       
       
       Gem files will remain installed in /code/repos/165069/gems_build/gems/rmagick-2.13.1 for inspection.
       Results logged to /code/repos/165069/gems_build/gems/rmagick-2.13.1/ext/RMagick/gem_make.out


error: hooks/pre-receive exited with error code 1
To git@heroku.com:mm-alpha.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'git@heroku.com:mm-alpha.git'
mj:~/work/mm/github/mm mark$ 

======

mj:~/work/mm/github/mm mark$ more .gems
rmagick
authlogic --version 2.1.3
rubyzip --version 0.9.4
subdomain-fu --version 0.5.4
memcached
will_paginate
cancan
faker
mj:~/work/mm/github/mm mark$