error[E0425]: cannot find function `bar` in module `a`
  --> $DIR/macro-outer-attributes.rs:18:8
   |
LL |     a::bar();
   |        ^^^ not found in `a`
   |
help: consider importing this function
   |
LL + use b::bar;
   |
help: if you import `bar`, refer to it directly
   |
LL -     a::bar();
LL +     bar();
   |

error: aborting due to previous error

For more information about this error, try `rustc --explain E0425`.