Misleading error message when passing a reference to an FnOnce and a non-reference is expected

[illicitonion]

Compiling this code:

struct Foo {}

impl Foo {
    pub fn foo(&self) -> String {
        "foo".to_owned()
    }
}

fn main() {
    let foo = Foo{};
    let closure = move || foo;

    call(&closure);
}

fn call<F: FnOnce() -> Foo>(f: F) {
    println!("{}", f().foo())
}

gives me the following error:

error[E0525]: expected a closure that implements the `Fn` trait, but this closure only implements `FnOnce`
  --> src/main.rs:11:19
   |
11 |     let closure = move || foo;
   |                   ^^^^^^^^^^^
12 | 
13 |     call(&closure);
   |     ---- the requirement to implement `Fn` derives from here
   |
note: closure is `FnOnce` because it moves the variable `foo` out of its environment
  --> src/main.rs:11:27
   |
11 |     let closure = move || foo;
   |                           ^^^

call does expect a closure which implements FnOnce, not one which implements Fn as the error message suggests. Accordingly, the line "expected a closure that implements the Fn trait, but this closure only implements FnOnce" is very misleading.

The actual problem here is that a reference to an FnOnce is being passed, rather than the FnOnce itself. It would be great if the error message reflected this fact.

[estebank]

Current output, still incorrect:

error[E0525]: expected a closure that implements the `Fn` trait, but this closure only implements `FnOnce`
  --> src/main.rs:11:19
   |
11 |     let closure = move || foo;
   |                   ^^^^^^^^---
   |                   |       |
   |                   |       closure is `FnOnce` because it moves the variable `foo` out of its environment
   |                   this closure implements `FnOnce`, not `Fn`
12 | 
13 |     call(&closure);
   |     ---- the requirement to implement `Fn` derives from here