| error[E0599]: cannot write into `String` | 
 |   --> $DIR/missing-writer-issue-139830.rs:7:20 | 
 |    | | 
 | LL |     let _ = write!(buf, "foo"); | 
 |    |                    ^^^ | 
 |    | | 
 |   --> $SRC_DIR/core/src/fmt/mod.rs:LL:COL | 
 |    | | 
 |    = note: the method is available for `String` here | 
 | note: must implement `io::Write`, `fmt::Write`, or have a `write_fmt` method | 
 |   --> $DIR/missing-writer-issue-139830.rs:7:20 | 
 |    | | 
 | LL |     let _ = write!(buf, "foo"); | 
 |    |                    ^^^ | 
 |    = help: items from traits can only be used if the trait is in scope | 
 | help: trait `Write` which provides `write_fmt` is implemented but not in scope; perhaps you want to import it | 
 |    | | 
 | LL + use std::fmt::Write; | 
 |    | | 
 |  | 
 | error: aborting due to 1 previous error | 
 |  | 
 | For more information about this error, try `rustc --explain E0599`. |