<!-- Thank you for submitting a bootstrap report! Please provide detailed information to help us reproduce and diagnose the issue. --> ### Summary `./x test clippy` does not support filtering tests the way other test suites do, by passing `--test-args`. ### Command used ```sh ./x test clippy --stage 1 --test-args line ``` ### Expected behaviour Only the tests with the word "line" in the file get run. (C.f. `./x test miri -- atomic`). ### Actual behaviour All tests get run. ### More details The logic that makes this work in Miri is here: https://github.com/rust-lang/rust/blob/d6179022c1d86f6c3e63a64933dff2734b366935/src/bootstrap/src/core/build_steps/test.rs#L685 There's something in clippy that seems related but I don't understand any part of it: https://github.com/rust-lang/rust/blob/d6179022c1d86f6c3e63a64933dff2734b366935/src/bootstrap/src/core/build_steps/test.rs#L792-L807 Also the logic inside clippy's ui test runner is odd -- usually, Rust test suites take their test filter form the command-line arguments. Here's Miri doing that: https://github.com/rust-lang/rust/blob/db617afe8b188e3c08a26f40a3662833a38e8c3c/src/tools/miri/tests/ui.rs#L159 We don't even have to do anything, ui_test just does this by default. Clippy also does this... https://github.com/rust-lang/rust/blob/3ee43259ac9ddb7d5e050e9c7e65c848550045da/src/tools/clippy/tests/compile-test.rs#L112 ... but then it overwrites the resulting filter for some reason: https://github.com/rust-lang/rust/blob/3ee43259ac9ddb7d5e050e9c7e65c848550045da/src/tools/clippy/tests/compile-test.rs#L118 Is there a reason clippy makes this different from every other crate I have ever seen? Cc @flip1995 @oli-obk @Kobzol