Regression in the move to python3 is happening all the time, and it is indeed very annoying.
Making a test target and a buildbot may be easier once at least all our cython files are correctly cythonized in py3. This is blocked by the removal of cmp() in all .pyx files. Not an easy task, as the remaining instances involve coercion, parents and elements. Experts would be welcome to help.
I would also like that the doctests are run using the python3 syntax for print. Does anybody know how to do that ? A priori, all tests should pass.
If this is possible, the next thing to do will be to run doctests with the range turned into an iterator. In this case, some tests still need care to pass.