Re: title, I don’t know how to phrase it best.  What exactly is the behavior you request?  I put “handle” as in “do the right thing”, that is, “don’t install the newest version but the one that satisfies all predicates”.  I softened “conflicts” to “incompatibilities”, does it work for you?  In any case, the important thing is that your report describes the problem well.

Re: 404, it has moved to http://distutils2.notmyidea.org/library/distutils2.depgraph.html