setuptools: Install fails with KeyError: 'processor_architecture'

Started after yesterdays update

Downloading https://pypi.io/packages/source/s/setuptools/setuptools-24.0.0.zip
Extracting in /tmp/tmpmNBMZ1
Now working in /tmp/tmpmNBMZ1/setuptools-24.0.0
Installing Setuptools
Traceback (most recent call last):
  File "setup.py", line 21, in <module>
    exec(init_file.read(), command_ns)
  File "<string>", line 11, in <module>
  File "/tmp/tmpmNBMZ1/setuptools-24.0.0/setuptools/__init__.py", line 14, in <module>
    from setuptools.extension import Extension
  File "/tmp/tmpmNBMZ1/setuptools-24.0.0/setuptools/extension.py", line 11, in <module>
    from . import msvc
  File "/tmp/tmpmNBMZ1/setuptools-24.0.0/setuptools/msvc.py", line 244, in <module>
    class PlatformInfo:
  File "/tmp/tmpmNBMZ1/setuptools-24.0.0/setuptools/msvc.py", line 253, in PlatformInfo
    current_cpu = safe_env['processor_architecture'].lower()
  File "/usr/lib/python2.7/UserDict.py", line 23, in __getitem__
    raise KeyError(key)
KeyError: 'processor_architecture'
Something went wrong during the installation.
See the error message above.