Honest question, how can it possibly take 10 years to port hg to Python 3? If I am to believe the Wikipedia source for the first release of Mercurial[0], it would've been only 4 years old at the start of the 10 year porting process. How on earth does it take 10 years to port 4 year old software?

Even taking into account the fact that new features were still being added and not all focus was on porting, this doesn't really seem like a reasonable representation of what's going on; I have a suspicion that "10 years" of porting here does not entail nearly as much work as it seems.

[0] https://lkml.org/lkml/2005/4/20/45