django-compressor bundles cssmin which is available as a separate package in Fedora. Patching to use the system one should be straightforward, maybe all that's needed is removal of the bundled cssmin.py, adjusting CSSMinFilter.callback in compressor/filters/cssmin/__init__.py, and adding appropriate python*-cssmin dependencies. https://fedoraproject.org/wiki/Packaging:No_Bundled_Libraries#When_a_Bundled_Library_is_Discovered_Post-Review
This bug appears to have been reported against 'rawhide' during the Fedora 24 development cycle. Changing version to '24'. More information and reason for this action is here: https://fedoraproject.org/wiki/Fedora_Program_Management/HouseKeeping/Fedora24#Rawhide_Rebase
I just looked into this, and it already seems to be fixed (at least in F24+)