This repo contains a dependency set up to illustrate a limitation / bug in pip. The dependencies are like so:

intermediate-package:
    boto==2.3.0

main-package:
    boto>=2.3.0
    intermediate-package

The issue is that pip install main-package will install boto-2.5.2 when boto-2.3.0 is the version that makes sense.

Exact steps to reproduce, starting in a clone of this repo:

mkvirtualenv pip-version-issue
(cd intermediate-package && python setup.py sdist)
cp intermediate-package/dist/*.tar.gz fake-pypi/intermediate-package/
pip install --extra-index-url "file://$PWD/fake-pypi" -e main-package

You'll see stuff installed, including boto-2.5.2, and then output like this:

Successfully installed boto intermediate-package main-package
Cleaning up...

But intermediate-package does not have its requirements met.