improve wording of "possible candidate is found in another module" with enums

[comex]

When compiling:

enum E { Foo }
fn main() {
    println!("{}", Foo);
}

rustc currently produces:

error[E0425]: cannot find value `Foo` in this scope
 --> src/main.rs:3:20
  |
3 |     println!("{}", Foo);
  |                    ^^^ not found in this scope
help: possible candidate is found in another module, you can import it into scope
  |
1 | use E::Foo;
  |

This is a great error message except for one thing: the enum E is not really a "module" (even if it behaves like one for scoping purposes), so saying the candidate is "in another module" can be confusing. It would be better to modify the wording in this case.

[PramodBisht]

@comex do you have a specific diagnostic message in mind or should we consider replacing module with enum?

[comex]

Well, it might be worth suggesting replacing Foo with E::Foo, instead of or in addition to suggesting a use statement – since it seems that idiomatic Rust usually avoids importing enum variants into scope. But the main issue is just the wording.

[BGR360]

Looks like the gods of time have made things better:

Playground

enum E { Foo }
fn main() {
    println!("{}", Foo);
}

error[E0425]: cannot find value `Foo` in this scope
 --> src/main.rs:3:20
  |
3 |     println!("{}", Foo);
  |                    ^^^ not found in this scope
  |
help: consider importing this unit variant
  |
1 | use E::Foo;
  |

But I like @comex 's second idea: rather than suggesting an import statement, give an inline suggestion to use the fully-qualified path.

Should we only do this for enums?