c-c source-sync now actually force synchronization as advertized by its help message. This was because "force" argument wasn't considered by acquire_synchronization_lock().

version=3
opts=uversionmangle=s/(rc|a|b|c)/~$1/ \
http://pypi.debian.net/cubicweb/cubicweb-(.+)\.(?:zip|tgz|tbz|txz|(?:tar\.(?:gz|bz2|xz)))