title: cl.exe failed with exit status 2
body: <p>I have looked everywhere for a solution to this error. I'm no expert with python or programming but I have followed the various recommendations with no results. </p>
  
  <p>Tried adding cl.exe to my environment PATH bot user and system. </p>
  
  <p>Installed Microsoft Visual C++ tools 2015, after running the command the first time and getting that as a solution in the output. </p>
  
  <p>Also tried installing MinGW python distribution, a thread somewhere recommended it, and nothing. </p>
  
  <p>Was not sure if it was the CMD I used so tried both in the normal windows one as well as the package manager in visual studios, same error. </p>
  
  <p>From what I gather its a windows problem, but I've got no idea what that means in terms of finding a fix.</p>
  
  <pre><code>Microsoft Windows [Version 10.0.16299.192]
  (c) 2017 Microsoft Corporation. All rights reserved.
  
  C:\Users\User&gt;pip install rebound
  Collecting rebound
    Using cached rebound-3.5.12.tar.gz
  Building wheels for collected packages: rebound
    Running setup.py bdist_wheel for rebound ... error
    Complete output from command c:\users\user\appdata\local\programs\python\python36\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\User\\AppData\\Local\\Temp\\pip-build-h7n58o8k\\rebound\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d C:\Users\User\AppData\Local\Temp\tmpgvqt5nrzpip-wheel- --python-tag cp36:
    running bdist_wheel
    running build
    running build_py
    creating build
    creating build\lib.win-amd64-3.6
    creating build\lib.win-amd64-3.6\rebound
    copying rebound\data.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\debug.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\horizons.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\interruptible_pool.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\particle.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\plotting.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\simulation.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\simulationarchive.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\tools.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\units.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\widget.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\__init__.py -&gt; build\lib.win-amd64-3.6\rebound
    copying rebound\rebound.h -&gt; build\lib.win-amd64-3.6\rebound
    running build_ext
    building 'librebound' extension
    creating build\temp.win-amd64-3.6
    creating build\temp.win-amd64-3.6\Release
    creating build\temp.win-amd64-3.6\Release\src
    C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\x86_amd64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -DLIBREBOUND -Isrc -Ic:\users\user\appdata\local\programs\python\python36\include -Ic:\users\user\appdata\local\programs\python\python36\include "-IC:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" /Tcsrc/rebound.c /Fobuild\temp.win-amd64-3.6\Release\src/rebound.obj -fstrict-aliasing -O3 -std=c99 -Wno-unknown-pragmas -DGITHASH=c7087474e5b18039d66c506088164c06e2c3659e -DLIBREBOUND -D_GNU_SOURCE -fPIC
    cl : Command line error D8021 : invalid numeric argument '/Wno-unknown-pragmas'
    error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\x86_amd64\\cl.exe' failed with exit status 2
  
    ----------------------------------------
    Failed building wheel for rebound
    Running setup.py clean for rebound
  Failed to build rebound
  Installing collected packages: rebound
    Running setup.py install for rebound ... error
      Complete output from command c:\users\user\appdata\local\programs\python\python36\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\User\\AppData\\Local\\Temp\\pip-build-h7n58o8k\\rebound\\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\User\AppData\Local\Temp\pip-zpsleveu-record\install-record.txt --single-version-externally-managed --compile:
      running install
      running build
      running build_py
      creating build
      creating build\lib.win-amd64-3.6
      creating build\lib.win-amd64-3.6\rebound
      copying rebound\data.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\debug.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\horizons.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\interruptible_pool.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\particle.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\plotting.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\simulation.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\simulationarchive.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\tools.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\units.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\widget.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\__init__.py -&gt; build\lib.win-amd64-3.6\rebound
      copying rebound\rebound.h -&gt; build\lib.win-amd64-3.6\rebound
      running build_ext
      building 'librebound' extension
      creating build\temp.win-amd64-3.6
      creating build\temp.win-amd64-3.6\Release
      creating build\temp.win-amd64-3.6\Release\src
      C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\x86_amd64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -DLIBREBOUND -Isrc -Ic:\users\user\appdata\local\programs\python\python36\include -Ic:\users\user\appdata\local\programs\python\python36\include "-IC:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" /Tcsrc/rebound.c /Fobuild\temp.win-amd64-3.6\Release\src/rebound.obj -fstrict-aliasing -O3 -std=c99 -Wno-unknown-pragmas -DGITHASH=c7087474e5b18039d66c506088164c06e2c3659e -DLIBREBOUND -D_GNU_SOURCE -fPIC
      cl : Command line error D8021 : invalid numeric argument '/Wno-unknown-pragmas'
      error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\x86_amd64\\cl.exe' failed with exit status 2
  
      ----------------------------------------
  Command "c:\users\user\appdata\local\programs\python\python36\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\User\\AppData\\Local\\Temp\\pip-build-h7n58o8k\\rebound\\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\User\AppData\Local\Temp\pip-zpsleveu-record\install-record.txt --single-version-externally-managed --compile" failed with error code 1 in C:\Users\User\AppData\Local\Temp\pip-build-h7n58o8k\rebound\
  
  C:\Users\User&gt;
  </code></pre>