[klibertp]

> For example, I'd like to have a way to list all unresolved futures everywhere in Emacs, the way I can with e.g. external processes.

I think you could get this done by advising promise creation/resolution functions, aio-promise and aio-resolve. The async/await macros are wrappers around generators-over-promises in this library.

But yes, in general Emacs concurrency sucks. The least bad option I found was using promises' implementation (chuntaro/emacs-promise) that uses `cl-defgeneric` for `promise-then` and (obviously) moving as much processing to a subprocess as possible. The former allows you to make any type "thenable" by implementing the method for it, which is nice for bundling the state around async operations. cl-defstructs are nice for the purpose.