[NLL] loss of span for type outlives errors in closures/async blocks

@rustbot

Given the following code: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=aaf294b9353da9ea4ef76206ed0c0a76

fn test<'a, T>() {
    || {
        None::<&'a T>;
    };
}

The current output is:

error[E0309]: the parameter type `T` may not live long enough
 --> src/lib.rs:2:5
  |
2 | /     || {
3 | |         None::<&'a T>;
4 | |     };
  | |_____^ ...so that the type `T` will meet its required lifetime bounds
  |
help: consider adding an explicit lifetime bound...
  |
1 | fn test<'a, T: 'a>() {
  |              ++++

Ideally the output should look similar to when constraint is generated in the main fn body:

error[E0309]: the parameter type `T` may not live long enough
 --> src/lib.rs:3:9
  |
3 |         None::<&'a T>;
  |         ^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
  |
help: consider adding an explicit lifetime bound...
  |
1 | fn test<'a, T: 'a>() {
  |              ++++

@rustbot label A-NLL NLL-diagnostics D-terse regression-from-stable-to-beta

@jackh726

Regressed in #95565 cc @jackh726

searched nightlies: from nightly-2022-01-01 to nightly-2022-07-20
regressed nightly: nightly-2022-06-08
searched commit range: 50b0025...5435ed6
regressed commit: bb55bd4

bisected with cargo-bisect-rustc v0.6.3

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --start=2022-01-01 --script=./script.sh 

cat script.sh
#!/bin/sh
cargo check 2>&1 | grep "does not outlive the data it points at"

@rustbot

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-medium

@rustbot

@rustbot label -regression-from-stable-to-beta +regression-from-stable-to-stable

Auto merge of rust-lang#102618 - aliemjay:simplify-closure-promote, r…

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[NLL] loss of span for type outlives errors in closures/async blocks #99245

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[NLL] loss of span for type outlives errors in closures/async blocks #99245

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apiraino commented on Jul 20, 2022

apiraino commented on Jul 20, 2022

mqudsi commented on Aug 12, 2022

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