trait implementation conflicts depending on source crate with generic_const_exprs

I tried this code:

crate foo

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]

pub trait KnownSize: Sized {
    const N: usize = core::mem::size_of::<Self>();
}
impl<T: Sized> KnownSize for T {}

pub trait SizeIs<const N: usize> {}
impl<T: KnownSize> SizeIs<{ T::N }> for T {}

struct X(u32);

// Uncommenting either of these lines breaks due to conflict with blanket impls above
// impl KnownSize for X {}
// impl SizeIs<4> for X {}

crate bar

use foo::*;

struct X(u32);

// Uncommenting this line breaks due to conflict with blanket impl in `foo`
// impl KnownSize for X {}

// However this line works! (and is required if I want to use the `X: SizeIs<4>` impl)
impl SizeIs<4> for X {}

I expected to see this happen:
impl SizeIs<4> for X {} should work in both foo and bar, or in neither.
impl KnownSize for X {} and impl SizeIs<4> for X {} should either both work or neither work (in bar).

Meta

rustc --version --verbose:

rustc 1.76.0-nightly (6b771f6b5 2023-11-15)
binary: rustc
commit-hash: 6b771f6b5a6c8b03b6322a9c77ac77cb346148f0
commit-date: 2023-11-15
host: x86_64-unknown-linux-gnu
release: 1.76.0-nightly
LLVM version: 17.0.5

Start by reproducing the two-crate examples with the recorded rustc 1.76.0-nightly version, comparing the coherence errors for the KnownSize and SizeIs implementations in crates foo and bar. Trace the compiler's trait implementation conflict handling for generic_const_exprs; done means the source-crate-dependent behavior is explained and the expected consistency is covered by a regression test.