We have an issue in the runtime right now where we serialize closures
asynchronously, meaning we make it possible to form cycles between
resource graphs (something that ought to be impossible in our model,
where resources are "immutable" after creation and cannot form cycles).
Let me tell you a tale of debugging this ...
Well, no, let's not do that. But thankfully I've left behind some
little utilities that might make debugging such a thing easier down
the road. Namely:
* By default, most of our core runtime promises leverage a leak handler
that will log an error message should the process exit with certain
critical unresolved promises. This error message will include some
handy context (like whether it was an input promise) as well as a
stack trace for its point of creation.
* Optionally, with a flag in runtime/debuggable.ts, you may wire up
a hang detector, for situations where we may want to detect this
situation sooner than process exit, using the regular message loop.
This uses a defined timeout, prints the same diagnostics as the
leak detector when a hang is detected, and is disabled by default.