Always show the lint name involved in a diagnostic?

[Kannen]

Description

After the first occurrence of a lint, the name of the lint is not displayed anymore.

That is a real annoyance:

• When the diagnostics are shown in a console, one has to find out the first occurrence of the error.
• When the diagnostics are shown in an IDE, there is not such a thing as the first diagnostics so it is almost impossible to find out the name of the lint.

I do not see any good reason to optimize one line of such a useful information. (Or maybe there are still hobbyist using teleprinter and Altair 8800???).

Version

Additional Labels

No response

[y21]

For reference, this was an intentional decision made in #42919, but in any case, I'm moving this to the rust repo as the behavior of this note is inherited from/implemented in the compiler (and presumably you don't just want this for clippy lints specifically but also for e.g. rustc's dead_code lint warnings?), so not really actionable from the clippy side.

[clubby789]

Regarding the second point, at least with my VS Code + Rust-Analyzer config, the name of the lint is displayed inline on the first occurrence, and always displayed in the popup when mousing over the yellow squiggly

Regarding the request in general, I feel that the output when there's several lints is already quite busy and appreciate any reductions. I'd assume the lint name is generally exclusively needed when #[allow]ing - which IMO should be the less common case, as resolving them would generally be preferred; I think it's okay if a little more work is needed to identify the name

[jieyouxu]

This was intentional as discussed in #38103 (comment) and implemented in #42919, as it can become quite verbose if we repeat the lint name for each lint-related diagnostics.

Possibly, I could see maybe something like a compiler flag that requests all (main) lint diagnostics not omit lint names in follow-up diagnostics, but I don't think we'll want to do that as a default.