Invalid error help of struct generic param with default value

[A4-Tacks]

I tried this code:

struct Foo<T = i32>(&'static T);

I expected to see this happen:

help: consider adding an explicit lifetime bound
  |
1 | struct Foo<T: 'static = i32>(&'static T);
  |             +++++++++

Instead, this happened:

help: consider adding an explicit lifetime bound
  |
1 | struct Foo<T = i32: 'static>(&'static T);
  |                   +++++++++

is syntax error

Meta

(rust playground version):

1.80.0-nightly

(2024-05-05 9c9b568792ef20d8459c)