E0131 needs to be updated to new format

[sophiajt]

From:

Error E0131 needs a span_label, updating it from:

error[E0131]: main function is not allowed to have type parameters
  --> src/test/compile-fail/E0131.rs:11:1
   |
11 | fn main<T>() { //~ ERROR E0131
   | ^

To:

error[E0131]: main function is not allowed to have type parameters
  --> src/test/compile-fail/E0131.rs:11:1
   |
11 | fn main<T>() { //~ ERROR E0131
   | ^ main cannot have type parameters

Bonus: underline the type parameters directly

error[E0131]: main function is not allowed to have type parameters
  --> src/test/compile-fail/E0131.rs:11:1
   |
11 | fn main<T>() { //~ ERROR E0131
   |        ^^^ main cannot have type parameters

[Limeth]

I am working on this one.

[Limeth]

I need some help, I cannot get the label to display in the compilation error. I've asked around in #rust-internals, nobody answered apart from @TheZoq2 who seems to be experiencing the same problem and is looking for a solution too.
This is my code, where it doesn't work: Limeth@56c54cf#diff-34daa37d4433b778139b9c3bb583756bR269
This is someone else's code, where it does work: https://github.com/rust-lang/rust/pull/35288/files#diff-1d1b0d29a2e8da97c6bfb6e364d920c7R3397
@jonathandturner @GuillaumeGomez

[GuillaumeGomez]

@Limeth: You can take a look to #35264. It's very similar to this one.

[Limeth]

@GuillaumeGomez You did? I thought you had taken E0132 instead.

E0131 🔒 @Limeth
E0132 🔒 @GuillaumeGomez

[GuillaumeGomez]

@Limeth: Yes sorry, when I have read the description, I thought it was the one I did because they're very close. I updated my comment.

[leikahing]

@Limeth are you not seeing the messages show up next to the span? If so, can you try running your rustc like this?

RUST_NEW_ERROR_FORMAT=true ./build/PLATFORM-HERe/stage1/bin/rustc src/test/compile-fail/E0131.rs

I ran into the same issue - the new formatting and span labels aren't enabled by default yet.

[TheZoq2]

That made it work for me @birryree

[Limeth]

Yes, that was the reason. Thank you, @birryree!

[Limeth]

We've implemented essentially the same thing with @GuillaumeGomez in two separate PRs. I am now waiting for his PR to get merged, so we both can use the same implementation.
#35264

[GuillaumeGomez]

@Limeth: It should be merged in no time. Just hold on a bit more!