Using associated types on concrete types as parameters for trait impls causes incorrect type resolution

[dylanede]

This small example:

use ::std::borrow::ToOwned;

struct Foo;

impl From<<bool as ToOwned>::Owned> for Foo {
    fn from(v: <bool as ToOwned>::Owned) -> Foo {
        unimplemented!()
    }
}

causes the error E0119: "conflicting implementations of trait std::convert::From<Foo> for type Foo", though I have not written an implementation of From<Foo> anywhere. <bool as ToOwned>::Owned should be synonymous with bool, but in this case it doesn't appear to be, as replacing the first use of the associated type with bool stops the error.

I have observed this on stable, beta, and the latest nightly.

[Mark-Simulacrum]

Looks like a case of insufficient normalization.

[lcnr]

closing this as a duplicate of #85576 (comment). THanks for opening this issue 👍