pip install pygraphviz: No package 'libcgraph' found
<p>I succeed in installing <code>graphviz</code> and <code>cgraph</code> with</p>

<pre><code>$ sudo pip install graphviz
....
Successfully installed graphviz-0.5.1

$ sudo pip install cgraph
...
Successfully installed cgraph-0.1
</code></pre>

<p>I encounter the issue <code>No package 'libcgraph' found</code> while running <code>sudo pip install pygraphviz</code>. Below is the full stacktrace.</p>

<pre><code>$ sudo pip install pygraphviz
The directory '/Users/sparkandshine/Library/Caches/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/Users/sparkandshine/Library/Caches/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting pygraphviz
  Downloading pygraphviz-1.3.1.zip (123kB)
    100% |████████████████████████████████| 133kB 1.5MB/s 
Installing collected packages: pygraphviz
  Running setup.py install for pygraphviz ... error
    Complete output from command /usr/bin/python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-build-qfFpFG/pygraphviz/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-JmwjA6-record/install-record.txt --single-version-externally-managed --compile:
    running install
    Trying pkg-config
    Package libcgraph was not found in the pkg-config search path.
    Perhaps you should add the directory containing `libcgraph.pc'
    to the PKG_CONFIG_PATH environment variable
    No package 'libcgraph' found
    Traceback (most recent call last):
      File "&lt;string&gt;", line 1, in &lt;module&gt;
      File "/private/tmp/pip-build-qfFpFG/pygraphviz/setup.py", line 87, in &lt;module&gt;
        tests_require=['nose&gt;=0.10.1', 'doctest-ignore-unicode&gt;=0.1.0',],
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 151, in setup
        dist.run_commands()
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 953, in run_commands
        self.run_command(cmd)
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
        cmd_obj.run()
      File "setup_commands.py", line 44, in modified_run
        self.include_path, self.library_path = get_graphviz_dirs()
      File "setup_extra.py", line 121, in get_graphviz_dirs
        include_dirs, library_dirs = _pkg_config()
      File "setup_extra.py", line 44, in _pkg_config
        output = S.check_output(['pkg-config', '--libs-only-L', 'libcgraph'])
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 573, in check_output
        raise CalledProcessError(retcode, cmd, output=output)
    subprocess.CalledProcessError: Command '['pkg-config', '--libs-only-L', 'libcgraph']' returned non-zero exit status 1

    ----------------------------------------
Command "/usr/bin/python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-build-qfFpFG/pygraphviz/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-JmwjA6-record/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/tmp/pip-build-qfFpFG/pygraphviz/
</code></pre>

<p>I tried the solutions provided by <a href="https://stackoverflow.com/questions/15661384/python-does-not-see-pygraphviz">Python does not see pygraphviz</a>, but it doesn't work. </p>