Comment 6 for bug 1200670

https://launchpad.net/~cjwatson/+archive/backports has a suitable source package of python-debian now, and should have binary packages including python3-debian in an hour or so. I suggest copying it from there to the SDK PPA using https://launchpad.net/~cjwatson/+archive/backports/+copy-packages (for efficiency, wait until my binaries have built and then "Copy existing binaries").