error[E0405]: cannot find trait `Error` in this scope --> $DIR/issue-102946.rs:1:6 | LL | impl Error for str::Utf8Error { | ^^^^^ not found in this scope | help: consider importing this trait | LL + use std::error::Error; | error[E0223]: ambiguous associated type --> $DIR/issue-102946.rs:1:16 | LL | impl Error for str::Utf8Error { | ^^^^^^^^^^^^^^ | help: you are looking for the module in `std`, not the primitive type | LL | impl Error for std::str::Utf8Error { | +++++ error: aborting due to 2 previous errors Some errors have detailed explanations: E0223, E0405. For more information about an error, try `rustc --explain E0223`.