error[E0432]: unresolved import `nonexistent_module`
  --> $DIR/issue-53269.rs:6:9
   |
LL |     use nonexistent_module::mac;
   |         ^^^^^^^^^^^^^^^^^^ you might be missing crate `nonexistent_module`
   |
help: consider importing the `nonexistent_module` crate
   |
LL + extern crate nonexistent_module;
   |

error[E0659]: `mac` is ambiguous
  --> $DIR/issue-53269.rs:8:5
   |
LL |     mac!();
   |     ^^^ ambiguous name
   |
   = note: ambiguous because of a conflict between a `macro_rules` name and a non-`macro_rules` name from another module
note: `mac` could refer to the macro defined here
  --> $DIR/issue-53269.rs:3:1
   |
LL | macro_rules! mac { () => () }
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: `mac` could also refer to the unresolved item imported here
  --> $DIR/issue-53269.rs:6:9
   |
LL |     use nonexistent_module::mac;
   |         ^^^^^^^^^^^^^^^^^^^^^^^
   = help: use `self::mac` to refer to this unresolved item unambiguously

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0432, E0659.
For more information about an error, try `rustc --explain E0432`.