Incorrect error message when `decl_macro` macro refers to `macro_rules!` macro

Playground link

#![feature(decl_macro)]

macro_rules! inner {
    () => {}
}

macro outer() {
    inner!();
}

outer!();

This code results in this confusing and completely incorrect error message:

error: cannot find macro `inner` in this scope
  --> src/lib.rs:10:5
   |
10 |     inner!();
   |     ^^^^^ consider moving the definition of `inner` before this call
...
15 | outer!();
   | -------- in this macro invocation
   |
note: a macro with the same name exists, but it appears later
  --> src/lib.rs:5:14
   |
 5 | macro_rules! inner {
   |              ^^^^^
   = note: this error originates in the macro `outer` (in Nightly builds, run with -Z macro-backtrace for more info)

Obviously, the definition of inner doesn't "appear later" than the definition of outer. In fact, the problem has nothing to do with definition order. The real fix is to add use inner; anywhere after the definition of inner.

(As a side note, I don't know if this is the intended behavior of macros 2.0, or a bug / current limitation of the nightly feature)

Start by running the linked Rust Playground example on nightly and compare the diagnostic with the reported output. Trace the compiler's diagnostic and name-resolution handling for a decl_macro referring to a macro_rules! macro. Done means the error no longer incorrectly attributes the problem to definition order and instead explains the required import or actual limitation.