title: Cython: Update to 0.20
body: <p>I upgraded cython to 0.20 via <code>pip install --upgrade cython</code>. Before it was just working fine. Then I couldn't compile anymore. Then I tried to uninstall an reinstall an got this <code>Unable to find vcvarsall.bat</code> error which wasn't there when installing cython 0.19...Come to think about it, 0.19 was installed with python(x, y) installation.</p>
  
  <pre><code>C:\&gt;gcc -v
  Using built-in specs.
  COLLECT_GCC=gcc
  COLLECT_LTO_WRAPPER=c:/mingw32-xy/bin/../libexec/gcc/mingw32/4.5.2/lto-wrapper.e
  xe
  Target: mingw32
  Configured with: ../gcc-4.5.2/configure --enable-languages=c,c++,ada,fortran,obj
  c,obj-c++ --disable-sjlj-exceptions --with-dwarf2 --enable-shared --enable-libgo
  mp --disable-win32-registry --enable-libstdcxx-debug --enable-version-specific-r
  untime-libs --disable-werror --build=mingw32 --prefix=/mingw
  Thread model: win32
  gcc version 4.5.2 (GCC)
  C:\&gt;ver
  
  Microsoft Windows [Version 6.1.7601]
  C:\&gt;python
  Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win
  32
  </code></pre>
  
  <p>I followed the instructions <a href="https://stackoverflow.com/a/16980330/1797098">here</a>, but not luck. Any ideas? Any more info I can provide?</p>