duplicate definition error depends on macro declaration order

Consider this code:

macro_rules! m { () => { mod Foo {} } }
struct Foo {}
m!();

The error is, "a module named Foo has already been defined in this module", pointing at line 2, the struct definition. Note that from, I would say, a user's perspective, the module is actually declared after the struct (by calling the macro).

Furthermore, switching lines 1 and 2 (not lines 2 and 3) switches the blame to the mod as being a duplicate.

1. error[E0428]: the name `Foo` is defined multiple times
    --> src/lib.rs:2:1
     |
   1 | macro_rules! m { () => { mod Foo {} } }
     |                          ------- previous definition of the module `Foo` here
   2 | struct Foo {}
     | ^^^^^^^^^^ `Foo` redefined here
     |
     = note: `Foo` must be defined only once in the type namespace of this module
   

   Esteban Kuber at 2023-07-28 12:53:36