Clippy ignores crate wide warn/deny

[tcharding]

I put this code in main.rs

#![deny(clippy::print_stdout)]

mod foo;

#[allow(clippy::print_stdout)]
fn main() {
    println!("Hello, world!");
}

And this code in foo.rs

pub fn foo() {
    println!("This should trigger clippy");
}

I expected to see clippy warn something like

error: use of `println!`
 --> src/foo.rs:2:5
  |
6 |     println!("This should trigger clippy");
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^

Instead all I get is

warning: function is never used: `foo`

Meta

cargo clippy -V                                                                                                            ✘ 101 
clippy 0.1.51 (4253153 2021-01-17)
rustc -Vv
rustc 1.51.0-nightly (4253153db 2021-01-17)
binary: rustc
commit-hash: 4253153db205251f72ea4493687a31e04a2a8ca0
commit-date: 2021-01-17
host: x86_64-unknown-linux-gnu
release: 1.51.0-nightly
LLVM version: 11.0.1

[giraffate]

It seems to be similar to #5356.

[flip1995]

Yes this is the same underlying issue. The solution is to get rid of pre_expansion_pass lints.

[davepacheco]

I think I ran into this too and reproduced it here: https://github.com/davepacheco/clippy-issue

@giraffate and @flip1995 you said this is the same underlying issue as #5356, but that one looks like it's been fixed. Do you expect this issue is fixed too? I'm still seeing it on clippy 0.0.212 (e1884a8e 2020-12-29) (Rust stable 1.49.0).

This doesn't always seem to be a problem and I'm not sure why not. I have a different crate (dropshot) that uses a crate-wide #![allow(clippy::style)] that appears to work.

[flip1995]

It's the same underlying issue, but requires a separate fix, which involves quite a bit of work. TL;DR the whole lint has to be rewritten.

[davepacheco]

Thanks for clarifying!

[jszwedko]

In case it helps others, as a work around I ended up adding these lints to .cargo/config.toml:

[target.'cfg(feature = "cargo-clippy")']
rustflags = [
  "-Dclippy::print_stdout",
  "-Dclippy::print_stderr",
  "-Dclippy::dbg_macro",
]