error[E0599]: no method named `exec` found for mutable reference `&mut Command` in the current scope --> $DIR/issue-39175.rs:14:39 | LL | Command::new("echo").arg("hello").exec(); | ^^^^ method not found in `&mut Command` | = help: items from traits can only be used if the trait is in scope help: the following trait is implemented but not in scope; perhaps add a `use` for it: | LL | use std::os::unix::process::CommandExt; | error: aborting due to previous error For more information about this error, try `rustc --explain E0599`.