error[E0133]: call to unsafe function `foo` is unsafe and requires unsafe function or block --> $DIR/const-extern-fn-requires-unsafe.rs:12:5 | LL | foo(); | ^^^^^ call to unsafe function | = note: consult the function's documentation for information on how to avoid undefined behavior error[E0133]: call to unsafe function `foo` is unsafe and requires unsafe function or block --> $DIR/const-extern-fn-requires-unsafe.rs:9:17 | LL | let a: [u8; foo()]; | ^^^^^ call to unsafe function | = note: consult the function's documentation for information on how to avoid undefined behavior error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0133`.