[rust-lang/rust] [ICE]: `ptr_metadata_ty_or_tail applied to unexpected type`

### ROOT CAUSE The issue arises from a recursive type definition where `Bar::Assoc2` refers back to itself through a `Result`, causing an infinite recursion during type evaluation. This leads to a compiler crash due to an internal error in handling the recursive type. ### CODE FIX To fix this, we need to break the recursion by defining `Bar::Assoc2` as a non-recursive type. Here's the corrected code: ```rust trait Trait { type Assoc2; } struct Bar; impl Trait for Bar { type Assoc2 = Result<(), ()>; // Changed to a non-recursive type } struct Foo { field: ::Assoc2, } static BAR: u8 = 42; static FOO2: &Foo = unsafe { std::mem::transmute(&BAR) }; fn main() {} ``` This change replaces the recursive `Result` type with a non-recursive one, preventing the infinite recursion and the subsequent compiler error.