Confusing error message combining when arrays, size_of in a container

[MikailBag]

Playground: https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=ff721dd90338cf7cfa30b9fe7198db36
This code tries to use [u8; std::mem::size_of::<T>()], where T is generic parameter. This is currently not supported, so for
good function compiler gives helpful error: constant expression depends on a generic parameter.
However, for functions bad1 and bad2 (where ill-formed array declaration is wrapped into other type), compiler gives error the size for values of type T cannot be known at compilation time. Furthermore, it suggests to add Sized bound, while it is already specified. I think this message and suggestion can be confusing.

Meta

I used rust v1.45.2 on the Rust Playground.

[lcnr]

This has the same underlying reason as #62708 and should hopefully be converted to a more accurate error once we start stabilizing min_const_generics.

[ghost]

A "container" is not required. This also results in confusing error message:

fn not_good<T: Sized>(x: T) {
    let _: [u8; std::mem::size_of::<T>()];
}

Edit: #80062's error message also contains this, and that code also doesn't have a "container".
Edit: This seems fixed in latest nightly. I'm late, just like in #62708. Sorry for the noise.
Edit: Unhiding since hopefully my example may be helpful for a test case.