When installing virtualenvwrapper on unstable, it requires stevedore, which itself depends on pbr. The ebuild of stevedore-1.6.0 requires: >=dev-python/pbr-0.8.0[${PYTHON_USEDEP}] <dev-python/pbr-1.0.0[${PYTHON_USEDEP}] In the source of stevedore-1.6.0 in the requieremnts.txt you can find: pbr<2.0,>=0.11 That is, the ebuild has to be changed accordingly, please. Reproducible: Always Steps to Reproduce: 1. install virtualenvwrapper 2. look at blocking messages from emerge 3.
fixed in 1.6.0-r1