I kinda see myself wanting the pip-tools flow, requirements.in -> pip compile -> requirements.txt thing perhaps integrated into pip itself. Seems like the simplest of the solutions out there for good dependency declarations and pinning? I may well be wrong.
It is, but it doesn't really bother me that it's not part of pip itself. On the other hand, I wouldn't be opposed to it being part of pip and "blessed" in that way.