error: `macro_two` is already in scope
  --> $DIR/macro-shadowing.rs:12:5
   |
LL |     #[macro_use]
   |     ^^^^^^^^^^^^
...
LL | m1!();
   | ----- in this macro invocation
   |
   = note: macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)
   = note: this error originates in the macro `m1` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0659]: `foo` is ambiguous
  --> $DIR/macro-shadowing.rs:17:1
   |
LL | foo!();
   | ^^^ ambiguous name
   |
   = note: ambiguous because of a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution
note: `foo` could refer to the macro defined here
  --> $DIR/macro-shadowing.rs:10:5
   |
LL |     macro_rules! foo { () => {} }
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
LL | m1!();
   | ----- in this macro invocation
note: `foo` could also refer to the macro defined here
  --> $DIR/macro-shadowing.rs:5:1
   |
LL | macro_rules! foo { () => {} }
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: this error originates in the macro `m1` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0659`.