Lifetime error missing information about where 'static bound is coming from

[fintelia]

Given the following code (Playground Link):

fn foo<T: 'static>(_t: T) {}

fn main() {
    let mut buf: Vec<u8> = Vec::new();
    let cursor = std::io::Cursor::new(&mut buf);

    foo(cursor);
}

The current output is:

   Compiling playground v0.0.1 (/playground)
error[E0597]: `buf` does not live long enough
 --> src/main.rs:5:39
  |
5 |     let cursor = std::io::Cursor::new(&mut buf);
  |                  ---------------------^^^^^^^^-
  |                  |                    |
  |                  |                    borrowed value does not live long enough
  |                  argument requires that `buf` is borrowed for `'static`
...
8 | }
  | - `buf` dropped here while still borrowed

For more information about this error, try `rustc --explain E0597`.
error: could not compile `playground` due to previous error

Ideally the output should look like:

  --> src/main.rs:8:39
   |
5  |     let cursor = std::io::Cursor::new(&mut buf);
   |                                       ^^^^^^^^-
   |                                       |
   |                                       borrowed value does not live long enough
...
7  |     foo(cursor);
   |     ^^^^^^^^
   |     |
   |     function call requires that `buf` is borrowed for `'static`
...
8  | }
   | - `buf` dropped here while still borrowed

(Or some other way of pointing out that line 11 is why the 'static bound is needed).

This is a simplified version of the code from image-rs/image-png#315

[not-my-profile]

This appears to have been fixed. The current output on stable is:

error[E0597]: `buf` does not live long enough
 --> src/main.rs:5:39
  |
4 |     let mut buf: Vec<u8> = Vec::new();
  |         ------- binding `buf` declared here
5 |     let cursor = std::io::Cursor::new(&mut buf);
  |                                       ^^^^^^^^ borrowed value does not live long enough
6 |
7 |     foo(cursor);
  |     ----------- argument requires that `buf` is borrowed for `'static`
8 | }
  | - `buf` dropped here while still borrowed