False positive for `await_holding_refcell_ref`

[Daniel-B-Smith]

I tried this code:

let mut state = self.state.borrow_mut();
let handles = state.cancel_all_in_flight();
drop(state);
let to_cancel = handles.len();
let cancelled = stream::iter(handles).then(|f| f).count().await;

I expected to see this happen: No error since the RefMut is explicitly dropped before the await

Instead, this happened: Brought up a warning

This happens in the recently promoted beta.

This should be pretty easy to fix. As a short term mitigation, I will downgrade the check from correctness and should hopefully be able to work on the fix next week.

[khuey]

Any progress here?

[Daniel-B-Smith]

Apologies for the lack of communication. From conversations on Zulip, it is in fact not an easy fix to identify variables that have been explicitly dropped. I intended to add the documentation quickly, but got caught up in things. I just sent out #6585. Unfortunately, I don't have the cycles to dig into this deeply right now.

[Ralith]

This lint seems to have been enabled by default in 1.61 and is still producing false positives, breaking my CI.