Hokay, so, Both #893817 and #896921 fall into the category "Tornado 5 incompatibility". Thomas's #893817 is specifically a ZeroMQ/Tornado 5 incompatibility which has since been fixed, but doing so revealed my #896921. To explain:
* February 10: ZeroMQ release pyzmq 17.0.0 to PyPI * March 22: Thomas files #893817 utilizing python3-zmq 16.0.2-2+b1, which is current for debian at the time * March 30: pyzmq 17.0.0-1 is accepted into debian unstable * April 4: pyzmq 17.0.0-1 is migrated to debian testing * April 25: I file #896921 utilizing the new python3-zmq, revealing the new problem Upstream is tracking general Tornado5 problems at https://github.com/saltstack/salt/issues/45790 as mentioned previously. The pull request https://github.com/saltstack/salt/pull/47106 should fix my #896921. It was merged April 25 into 2017.7, so should make it into the next point releases for 2017.7 and 2018.3. Thanks, Jamie
