Instability warning for let bindings in const fn doesn't list requisite feature flag · Issue #57544 · rust-lang/rust (original) (raw)

const fn foo() { let _x = 5; }

reports:

error: local variables in const fn are unstable
 --> src/lib.rs:2:9
  |
2 |     let _x = 5;
  |         ^^

error: aborting due to previous error

This should report to the user which feature flag should be added to use this feature.