[burntsushi]

Yes, I knew most of that. But the fact remains that they aren't complete yet and therefore can't actually be relied on as a dependency.

(N.B. I seem to recall someone telling me that gevent had been ported over a year ago and that all that remained was to just make a release. So count me skeptical until the port is complete.)

And that's just the most popular projects. Imagine what it looks like with the less popular projects? It isn't pretty. This is what the OP was talking about with the "tail" of Python projects.

N.B. I don't personally have this problem with less popular projects. I've always done my best to avoid depending on unmaintained or inactive projects because they tend to rot as time goes on (irrespective of massive changes like Python 2 and 3). But plenty of other people have this problem and it's definitely not an unreasonable problem to have.