The last release of sphinx (1.4.1) uses imagesize; so, it is needed.
python-module-imagesize-0.7.0-alt1 -> sisyphus: * Thu Apr 21 2016 Ivan Zakharyaschev <imz@altlinux> 0.7.0-alt1 - Initial build for ALT Sisyphus. (Needed for sphinx-1.4.1.) (ALT#31976) - The same source is used for both Python{2,3} with a commit from: https://github.com/xantares/imagesize_py/tree/py2a3