error[E0670]: `async fn` is not permitted in Rust 2015
  --> $DIR/drop-location-span-error-rust-2021-incompatible-closure-captures-96258.rs:8:16
   |
LL |     pub(crate) async fn new(
   |                ^^^^^ to use `async fn`, switch to Rust 2018 or later
   |
   = help: pass `--edition 2021` to `rustc`
   = note: for more on editions, read https://doc.rust-lang.org/edition-guide

error[E0412]: cannot find type `Duration` in this scope
  --> $DIR/drop-location-span-error-rust-2021-incompatible-closure-captures-96258.rs:10:19
   |
LL |         interval: Duration,
   |                   ^^^^^^^^ not found in this scope
   |
help: consider importing this struct
   |
LL + use std::time::Duration;
   |

warning: changes to closure capture in Rust 2021 will affect drop order
  --> $DIR/drop-location-span-error-rust-2021-incompatible-closure-captures-96258.rs:12:19
   |
LL |           interval: Duration,
   |           -------- in Rust 2018, this causes the closure to capture `interval`, but in Rust 2021, it has no effect
LL |
LL |       ) -> Numberer {
   |  _________________-_^
   | |                 |
   | |                 in Rust 2018, `interval` is dropped here along with the closure, but in Rust 2021 `interval` is not part of the closure
LL | |         Numberer {}
LL | |     }
   | |_____^
   |
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
note: the lint level is defined here
  --> $DIR/drop-location-span-error-rust-2021-incompatible-closure-captures-96258.rs:1:9
   |
LL | #![warn(rust_2021_incompatible_closure_captures)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: add a dummy let to cause `interval` to be fully captured
   |
LL |     ) -> Numberer { let _ = &interval;
   |                     ++++++++++++++++++

error: aborting due to 2 previous errors; 1 warning emitted

Some errors have detailed explanations: E0412, E0670.
For more information about an error, try `rustc --explain E0412`.