Conflict implementation when upstream crate has any impl for any type_alias_impl_trait type

I tried this code:

/// in crate A
pub trait Test {}

struct A;

impl Test for A {}

pub type OpaqueA = impl Test;
pub fn decide_type() -> OpaqueA {
  A
}

pub trait Test2 {}

impl Test2 for OpaqueA {}


/// end of crate A


/// in crate B that depends on crate A

pub struct B;

impl Test2 for B {}

/// end of crate B

I expected to see this happen: compiled successfully

Instead, this happened: failed to compile crateB

error[E0119]: conflicting implementations of trait `crateA::Test2` for type `crateA::OpaqueA`

Meta

rustc --version --verbose:

rustc 1.77.0-nightly (bf8716f1c 2023-12-24)
binary: rustc
commit-hash: bf8716f1cd6416266807706bcae0ecb2e51c9d4a
commit-date: 2023-12-24
host: aarch64-apple-darwin
release: 1.77.0-nightly
LLVM version: 17.0.6

if I merge crate B into crate A, it compiles.

This code works on the previous nightly-2023-06-12 at least.

Start by reproducing the two-crate example from the issue with the reported rustc 1.77.0 nightly, then compare it with nightly-2023-06-12. Investigate the conflict involving the impl for crateA::OpaqueA and the downstream impl for B; done means the valid two-crate example compiles without the erroneous E0119 conflict.