PyQt5 installed into system python, on Linux, Windows or OSX.
Make sure pip and setuptools are up to date
(my-virtualenv) $ pip install -U pip setuptools
Allow virtualenv to access PyQt5
(my-virtualenv) $ pip install vext.pyqt5
Qt5 on Ubuntu seems to only be available for python3, which at the time of writing is not supported by vext. [Dec 2015]
Report bugs to the vext project
This is Experimental I haven't used PyQt5 much, feedback, patches welcome :)