title: Installation for pygraphviz failed with Python 3.6 on Windows 10
body: <p><strong>Environment:</strong> </p>
  
  <ul>
  <li><p>Windows 10 pro</p></li>
  <li><p>graphviz version:
  dot - graphviz version 2.38.0 (20140413.2041)</p></li>
  <li><p>Python 3.6.2</p></li>
  </ul>
  
  <p><strong>ERROR OUTPUT:</strong></p>
  
  <pre><code>PS E:\VSCode_workpalce&gt; pip install pygraphviz
  Collecting pygraphviz
    Using cached pygraphviz-1.3.1.zip
  Installing collected packages: pygraphviz
    Running setup.py install for pygraphviz ... error
      Complete output from command e:\python\python36\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\Maxwell\\AppData\\Local\\Temp\\pip-build-5yrqs95d\\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 C:\Users\Maxwell\AppData\Local\Temp\
  pip-5b8cfh0_-record\install-record.txt --single-version-externally-managed --compile:
      running install
      include_dirs=None
      library_dirs=None
      running build
      running build_py
      creating build
      creating build\lib.win-amd64-3.6
      creating build\lib.win-amd64-3.6\pygraphviz
      copying pygraphviz\agraph.py -&gt; build\lib.win-amd64-3.6\pygraphviz
      copying pygraphviz\graphviz.py -&gt; build\lib.win-amd64-3.6\pygraphviz
      copying pygraphviz\release.py -&gt; build\lib.win-amd64-3.6\pygraphviz
      copying pygraphviz\version.py -&gt; build\lib.win-amd64-3.6\pygraphviz
      copying pygraphviz\__init__.py -&gt; build\lib.win-amd64-3.6\pygraphviz
      creating build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_attributes.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_attribute_defaults.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_clear.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_drawing.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_edge_attributes.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_graph.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_html.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_layout.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_node_attributes.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_readwrite.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_string.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_subgraph.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\test_unicode.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      copying pygraphviz\tests\__init__.py -&gt; build\lib.win-amd64-3.6\pygraphviz\tests
      running egg_info
      writing pygraphviz.egg-info\PKG-INFO
      writing dependency_links to pygraphviz.egg-info\dependency_links.txt
      writing top-level names to pygraphviz.egg-info\top_level.txt
      reading manifest file 'pygraphviz.egg-info\SOURCES.txt'
      reading manifest template 'MANIFEST.in'
      warning: no previously-included files matching '*~' found anywhere in distribution
      warning: no previously-included files matching '*.pyc' found anywhere in distribution
      warning: no previously-included files matching '.svn' found anywhere in distribution
      no previously-included directories found matching 'doc\build'
      writing manifest file 'pygraphviz.egg-info\SOURCES.txt'
      copying pygraphviz\graphviz.i -&gt; build\lib.win-amd64-3.6\pygraphviz
      copying pygraphviz\graphviz_wrap.c -&gt; build\lib.win-amd64-3.6\pygraphviz
      running build_ext
      building 'pygraphviz._graphviz' extension
      creating build\temp.win-amd64-3.6
      creating build\temp.win-amd64-3.6\Release
      creating build\temp.win-amd64-3.6\Release\pygraphviz
      cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -INone -Ie:\python\python36\include -Ie:\python\python36\include /Tcpygraphviz/graphviz_wrap.c /Fobuild\temp.win-amd64-3.6\Release\pygraphvi
  z/graphviz_wrap.obj
      error: command 'cl.exe' failed: No such file or directory
  
      ----------------------------------------
  Command "e:\python\python36\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\Maxwell\\AppData\\Local\\Temp\\pip-build-5yrqs95d\\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 C:\Users\Maxwell\AppData\Local\Temp\pip-5b8cfh0_-record\inst
  all-record.txt --single-version-externally-managed --compile" failed with error code 1 in C:\Users\Maxwell\AppData\Local\Temp\pip-build-5yrqs95d\pygraphviz\
  </code></pre>
  
  <p><strong>I do install the VC compiler for Python in VS2017 and can find the cl.exe manually BUT the installation still failed. Moreover, I have tried to build and install it by -c mingw32, it makes more ERRORs</strong>
  If anyone has any suggestions that would appreciate. </p>