Error looks unrelated. I believe @mattip is working on a fix.

CI failure is bizarre:

  File "c:\hostedtoolcache\windows\python\3.6.8\x64\lib\distutils\command\build_ext.py", line 473, in _build_extensions_serial
      self.build_extension(ext)
    File "setup.py", line 260, in build_extension
      build_ext.build_extension(self, ext)
    File "D:\a\1\s\numpy\distutils\command\build_ext.py", line 478, in build_extension
      unlinkable_fobjects)
    File "D:\a\1\s\numpy\distutils\command\build_ext.py", line 523, in _process_unlinkable_fobjects
      fobjects = [os.path.relpath(obj) for obj in unlinkable_fobjects]
    File "D:\a\1\s\numpy\distutils\command\build_ext.py", line 523, in <listcomp>
      fobjects = [os.path.relpath(obj) for obj in unlinkable_fobjects]
    File "c:\hostedtoolcache\windows\python\3.6.8\x64\lib\ntpath.py", line 584, in relpath
      path_drive, start_drive))
  ValueError: path is on mount 'c:', start on mount 'D:'

Looks like a real bug in numpy (not being installable across drive boundaries), but clearly not the fault of this PR.

Azure changed something. PR gh-16101 is waiting for review

Note this is pretty critical since the macos documentation checks are all run only if a preliminary windows run succeeds, so nep and doc PRs should not be merged till this is fixed

One slight curiosity is that np.log(0) should give a warning, because an inf is created. So arguable np.logaddexp.reduce([]) should also. We do not have that capability, and its not vital, just thought I would mention. This seems simple and good to go, unless anyone thinks it should have a release note?

Thanks for a nice first PR, looking forward to more! (Just waiting for the test to finish before merging).

Oh, I forgot about the potential inclusion in the release notes. @eriknw can you add a very short release note statement, as detailed in https://github.com/numpy/numpy/blob/master/doc/release/upcoming_changes/README.rst

Release note added. Sorry for the delay.

Thanks for the followup!

My pleasure, and thanks for being very welcoming, prompt, and helpful!