rustdoc reports issues against `lib.rs` rather than an `include_str!`'d file

[fasterthanlime]

The repro repository has everything: https://github.com/fasterthanlime/readme-md-error-reporting

Expected behavior is that the diagnostics have: --> README.md:7:16, but they currently have --> src/lib.rs:7:16.

[fasterthanlime]

cc @GuillaumeGomez (as per Mastodon discussion)

[GuillaumeGomez]

Thanks for opening the issue! I'm surprised since it's an issue that was supposed to be fixed in #123204. Just to confirm: which rustc version do you use?

Also cc @notriddle since you're the one who fixed this bug.

[fasterthanlime]

This happened with 1.81 most likely — I would take the few secs to check but I’m on a phone right now.

[notriddle]

The doctest system needs to use the same infrastructure as the rest of rustdoc.

[fasterthanlime]

I can confirm this does fix my repro:

Would you like a separate issue for the part where it says src/../README.md when really it could normalize the path and just say README.md ?

[GuillaumeGomez]

Yes please!

[fasterthanlime]

Yes please!

@GuillaumeGomez filed as #130626