@Winterflower: Thank you for encouraging @dsoprea to create the new PR and working to convert the previous patch.

@dsoprea: Thank you for taking the time to create the PR especially after this has been sitting unloved for so long.

Though the new workflow using PR's is still in a bit of a state of flux, my understanding is that we will want to have one PR per feature branch (i.e. one for each of 2.7, 3.6, 3.7) that we want to target.

Now that we seem to have spawned two parallel discussion tracks (one here and one in the PR https://github.com/python/cpython/pull/57), I'm not sure how best to resolve that but for the time being I'll offer code-related comments here as they're much more likely to be preserved (and thus discoverable) for posterity:  we do need some sort of tests around this to complete the patch -- something that would exercise both the non-exception and exception paths (and thus would detect that intended call to util.debug()).