I wonder how to have sane code reuse between patchcheck and Mercurial hooks. Mark seems to have started seconding Dirkjan with hooks, see e.g. 
http://hg.python.org/hooks/rev/0344575ad60e, so I wonder if we’re going to use only hooks (pro: they will be invoked on every push, whereas patchcheck is opt-in, con: they would require that contributors clone the hooks repo and set them up) or still maintain patchcheck, which has pros (no setup, does not require a VCS) and cons (not automatic, not widely used, whereas hooks can be part of the new python-dev policy).