Warn when a lint table has a group at the same priority as lints

[Alexendoo]

Problem

The sorting behaviour is causing confusion, me included as I thought this was a bug until I read the RFC

rust-lang/rust-clippy#11751 (comment)
rust-lang/rust-clippy#11237

Steps

No response

Possible Solution(s)

No response

Notes

No response

Version

No response

[epage]

This was left as a future possibility in the RFC.

To implement this, either cargo needs to pass the lints down to the tool in a way to communicate the priority batches, allow cargo to query the group memberships from the linter, or we hard code this at compile-time like rust-analyzer (lints, generate). One thing to keep in mind is the potential for custom tools in the future.

[kristof-mattei]

I'm confused by this.

[lints.rust]
dead-code = { level = "allow", priority = 1 }
warnings = { level = "deny", priority = 0 }

Does what I expect it to do

[lints.rust]
dead-code = { level = "allow", priority = 0 }
warnings = { level = "deny", priority = 1 }

Works just fine too.

I would expect that if I override a specific lint from a group that was included, that the override wins. Which is what Rust itself seems to do, regardless of sort order.

Only in the case of 2 groups disagreeing on a setting is when I would think to start using priorities.

[epage]

warnings is a dynamic group of everything that is currently set to warn.

[clayrab]

Is there a workaround for this in the meantime? I keep coming back around to this issue. I'm forced to just use -A flag on cargo directly and still can't seem to make anything work in config.toml or Cargo.toml.

[epage]

There is a PR for a clippy lint for when groups are the same priority as lints.

For why you are having difficulty, its hard to say without a reproduction case.

[andrewbanchich]

i'm not sure if this is a bug in this new behavior, but after updating to 1.78 i'm getting

error: lint group `pedantic` has the same priority (0) as a lint
   |
16 | pedantic = "warn"
   | ^^^^^^^^   ------ has an implicit priority of 0
17 | wildcard_enum_match_arm = "warn"
   | ----------------------- has the same priority as this lint
   |
   = note: the order of the lints in the table is ignored by Cargo
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#lint_groups_priority
help: to have lints override the group set `pedantic` to a lower priority
   |
16 | pedantic = { level = "warn", priority = -1 }

these both have the same level, so i'm not sure why it would need a priority. pedantic and wildcard_enum_match_arm are both allow by default, so i need this setting to enable them. wildcard_enum_match_arm is not in the pedantic group, so i'm not sure why i'd need to set a priority for one over the other.

[epage]

FYI that is a clippy lint and there is at least rust-lang/rust-clippy#12270 opened against it which is similar to what you are seeing.