pygraphvizのインストールでエラー

環境はMac OS X 10.7.2です

Graphvizのインストール

以下のURLからダウンロードできます
http://www.graphviz.org/Download_macos.php

pygraphvizのインストール

pip install pygraphviz

以下のエラーになりました

Downloading/unpacking pygraphviz
  Running setup.py egg_info for package pygraphviz
    /bin/sh: pkg-config: command not found
    /bin/sh: pkg-config: command not found
    Trying pkg-config
    Trying dotneato-config
    Failed to find dotneato-config
    
    Your Graphviz installation could not be found.
    
    1) You don't have Graphviz installed:
       Install Graphviz (http://graphviz.org)
    
    2) Your Graphviz package might incomplete.
       Install the binary development subpackage (e.g. libgraphviz-dev or similar.)
    
    3) You are using Windows
       There are no PyGraphviz binary packages for Windows but you might be
       able to build it from this source.  See
       http://networkx.lanl.gov/pygraphviz/reference/faq.html
    
    If you think your installation is correct you will need to manually
    change the include_path and library_path variables in setup.py to
    point to the correct locations of your graphviz installation.
    
    The current setting of library_path and include_path is:
    library_path=None
    include_path=None
    
    Traceback (most recent call last):
      File "<string>", line 14, in <module>
      File "#{file_path}/build/pygraphviz/setup.py", line 89, in <module>
        raise OSError,"Error locating graphviz."
    OSError: Error locating graphviz.
    Complete output from command python setup.py egg_info:
    /bin/sh: pkg-config: command not found

/bin/sh: pkg-config: command not found

Trying pkg-config

Trying dotneato-config

Failed to find dotneato-config



Your Graphviz installation could not be found.



1) You don't have Graphviz installed:

   Install Graphviz (http://graphviz.org)



2) Your Graphviz package might incomplete.

   Install the binary development subpackage (e.g. libgraphviz-dev or similar.)



3) You are using Windows

   There are no PyGraphviz binary packages for Windows but you might be

   able to build it from this source.  See

   http://networkx.lanl.gov/pygraphviz/reference/faq.html



If you think your installation is correct you will need to manually

change the include_path and library_path variables in setup.py to

point to the correct locations of your graphviz installation.



The current setting of library_path and include_path is:

library_path=None

include_path=None



Traceback (most recent call last):

  File "<string>", line 14, in <module>

  File "#{file_path}/build/pygraphviz/setup.py", line 89, in <module>

    raise OSError,"Error locating graphviz."

OSError: Error locating graphviz.

library_pathとinclude_pathを設定しろとありますので、setup.pyを開き、43、44行目のコメントを外します

# OSX, Linux, alternate location
#library_path='/usr/local/lib/graphviz'
#include_path='/usr/local/include/graphviz'

これでインストールできるようになりました。