The only way to fix this is to /not/ install *any* packages prior to resolving *all* dependencies ... which means that there needs to be a way to resolve the entire dependency graph for any given package in PyPI.

If PyPI provided a mechanism to fetch the entire dependency graph[1], then https://github.com/ActiveState/depgraph can be used to implement comprehensive dependency resolution. PyPM can do this because the PyPM repository provides a sqlite db containing dependency information for all packages and their versions.

Let me know if you need any assistance regarding ActiveState's depgraph implementation (I may have pending commits to be merged to the GitHub repo)

[1] I posted a few suggestions in regards to facilitating such exposure of static metadata in PyPI to distutils-sig@ - but until this day they remain as merely ideas.