error[E0433]: failed to resolve: use of undeclared crate or module `a`
  --> $DIR/macro-inner-attributes.rs:17:5
   |
LL |     a::bar();
   |     ^ use of undeclared crate or module `a`
   |
help: there is a crate or module with a similar name
   |
LL |     b::bar();
   |     ~

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0433`.