Distutils: ValueError: [u'path']

This is a really stupid error that occurs on Windows 64bit when trying to build extension modules using distutils:

  File "C:\Python27\lib\distutils\command\build_ext.py", line 340, in run
    self.build_extensions()
  File "setup.py", line 213, in build_extensions
    with_ext = self.check_extension_availability(ext)
  File "setup.py", line 239, in check_extension_availability
    depends=ext.depends)
  File "C:\Python27\lib\distutils\msvc9compiler.py", line 473, in compile
    self.initialize()
  File "C:\Python27\lib\distutils\msvc9compiler.py", line 383, in initialize
    vc_env = query_vcvarsall(VERSION, plat_spec)
  File "C:\Python27\lib\distutils\msvc9compiler.py", line 299, in query_vcvarsall
    raise ValueError(str(list(result.keys())))
ValueError: [u'path']

The workaround is to take the bat-file in C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\bin\vcvars32.bat and copy it to C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\bin\amd64\vcvarsamd64.bat. Not that easy to figure out!