The fix is in https://github.com/alexmojaki/executing/pull/97, which presumably requires python-executing to be updated 2.2.0 -> 2.2.1
This is reportedly a bug in src:python-executing, see
https://github.com/alexmojaki/stack_data/issues/59
- Bug#1123315: python-stack-data: FTBFS: dh_auto_... Santiago Vila
- Bug#1123315: (no subject) Gordon Ball
- Bug#1123315: marked as done (python-stack-... Debian Bug Tracking System

