Martin von Zweigbergk <martinvonz@google.com> [Mon, 14 Dec 2015 16:29:55 -0800] rev 1565
debian: don't refer to deleted tests/run-tests.py in debian/rules
tests/run-tests.py was deleted in 25a0c31882df (tests: remove the
custom run-tests.py, 2015-11-02), but we still refer to it in
debian/rules. Fix by having the user define a HGSRC variable when
calling 'debuild' (with e.g '-e HGSRC=~/hg').