Hello! I'm not sure whether it's a stack overflow but indeed our app was also broken when updating from 1.5.1 to 1.5.3. It's a complex app based on the Bevy game engine, where running it normally freezes, running it after locking the async-executor through cargo update -p async-executor --precise 1.5.1 works well.
It's a bit hard to understand what is happening and I don't want to bring in any red herring but bevy uses this executor to handle its tasks and it seems to get stuck in a sort of endless busy loop, without any significant memory leak but without any progress on the tasks it has assigned.

The app is here but I wouldn't really ask to run it and troubleshoot. Just thought I'd report the issue since we encountered it in a quite different package from the OP, so maybe it can shed some light.

Originally posted by @luca-della-vedova in #53 (comment)