error[E0658]: `async` blocks are not allowed in constants --> $DIR/issue-78722.rs:12:20 | LL | let f: F = async { 1 }; | ^^^^^^^^^^^ | = note: see issue #85368 for more information = help: add `#![feature(const_async_blocks)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date error[E0271]: expected `{async block@$DIR/issue-78722.rs:10:13: 10:18}` to be a future that resolves to `u8`, but it resolves to `()` --> $DIR/issue-78722.rs:8:30 | LL | fn concrete_use() -> F { | ^ expected `()`, found `u8` error: aborting due to 2 previous errors Some errors have detailed explanations: E0271, E0658. For more information about an error, try `rustc --explain E0271`.