Missing sys.path entries when setup.py uses setup_requires
When buildout develops an egg that both setup_requires and install_requires some package, scripts for that package don't work due to missing sys.path entries.
This is hard to describe in words, so I've attached a test case. Untar the archive and run ./reproduce.sh. It'll set up a virtualbox sandbox (to prevent your system Python from influencing the behaviour), bootstrap and run buildout, and will try to run the generated bin/testcase script, failing with an ImportError.
If you untar the archive in a fresh directory and remove the setup_requires line from setup.py before running ./reproduce.sh, bin/testcase will work fine.