cargo clippy not obeying [lints.clippy] from Cargo.toml, but only for some lints

[Kmeakin]

Summary

Clippy does not obey the lint_name = "allow" key under [lints.clippy] from Cargo.toml for certain lints, but does work as expected for others. The lints have to be silenced with #[allow(...)] instead.

In the example below, must_use_candidate obeys the [lints.clippy] settings, but wildcard_imports doesn't.

Other lints that don't obey [lints.clippy] that I have encountered:

• too_many_lines
• option_if_let_else

Reproducer

Cargo.toml:

[package]
name = "clippy-test"
version = "0.1.0"
edition = "2021"

[lints.clippy]
pedantic = "warn"

must_use_candidate = "allow"
wildcard_imports = "allow"

.cargo/config.toml:

[unstable]
lints = true

src/lib.rs:

mod foo {
    pub struct A;
}

// "usage of wildcard import" reported
use foo::*;

// "this function could have a `#[must_use]` attribute" not reported
pub fn a() -> A {
    A
}

Version

rustc 1.73.0-nightly (864bdf784 2023-07-25)
binary: rustc
commit-hash: 864bdf7843e1ceabc824ed86d97006acad6af643
commit-date: 2023-07-25
host: x86_64-unknown-linux-gnu
release: 1.73.0-nightly
LLVM version: 16.0.5

### Additional Labels

_No response_

[Alexendoo]

Looks like a cargo issue, it sorts the flags before passing them to clippy but the order matters

'--allow=clippy::wildcard_imports' '--warn=clippy::pedantic' '--allow=clippy::must_use_candidate'

[Alexendoo]

Closing in favour of rust-lang/cargo#12918

[kristof-mattei]

As posted here rust-lang/cargo#12918 (comment)

The behavior here seems different than rustc. rustc seems to consolidate the lints, apply groups and then the individual settings, whereas Clippy seems to go by the order of the params (and thus the priority).

Wouldn't it be better to match rustc's behavior?

[Alexendoo]

Clippy has no knowledge of the lint table, cargo turns it into --allow/--warn/etc flags the same as it would pass to rustc in cargo check/cargo build