error: invalid format string: unmatched `}` found --> $DIR/issue-86085.rs:4:12 | LL | format ! ( concat ! ( r#"lJ𐏿Æ�.𐏿�"# , "r} {}" ) ) ; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unmatched `}` in format string | = note: if you intended to print `}`, you can escape it using `}}` = note: this error originates in the macro `concat` (in Nightly builds, run with -Z macro-backtrace for more info) error: aborting due to 1 previous error