mimatched type when using a `let` binding with the same name as a struct

I tried this code:

use std::marker::*;

fn main() {
    let PhantomData = ();
}

I expected to see this happen: success! Or at least a better diagnostic message.

Instead, this happened: failure:

error[E0308]: mismatched types
 --> src/main.rs:4:9
  |
4 |     let PhantomData = ();
  |         ^^^^^^^^^^^   -- this expression has type `()`
  |         |
  |         expected `()`, found `PhantomData<_>`
  |
  = note: expected unit type `()`
                found struct `std::marker::PhantomData<_>`

Playground

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rustc --version --verbose:

rustc 1.80.0-nightly (791adf759 2024-05-21)
binary: rustc
commit-hash: 791adf759cc065316f054961875052d5bc03e16c
commit-date: 2024-05-21
host: x86_64-pc-windows-msvc
release: 1.80.0-nightly
LLVM version: 18.1.6

Start by reproducing the PhantomData example with the provided nightly rustc version or Playground link, then trace how the let binding is interpreted when it shares a name with the struct. Done means the example either compiles as expected or produces a more accurate diagnostic than the reported mismatched-types error.