[devtools/testlib] Issue a RuntimeError when a generative tests is detected Otherwise, generative tests *à la logilab-common* in CubicWebTC test cases would silently not run (at least using logilab.common.pytest runner).

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