Option to suppress unused variable warnings

[ghost]

I'm using built to get a few values, but even with the options tweaked to where I want them, I still get a lot of unused const warnings. (Especially when using Options{ env: true }...)

I'd appreciate it if there were an option to enable allow(unused_variables) without having to edit the file manually in build.rs.

I want to keep warnings enabled for my code, and most warnings for library code as well. But I'm well aware that I'm not using NUM_JOBS, I don't need to see that every time I build.

[lukaslueg]

Does it help if you use #[allow(unused_variables)] ?

#[allow(unused_variables)]
pub mod built_info {
    include!(concat!(env!("OUT_DIR"), "/built.rs"));
}

[ghost]

Earlier today hcpl on irc.mozilla.org#rust pointed out that my proposed solution would likely cause problems due to this issue: rust-lang/rust#18810

They also helped me solve the problem, and it turned out to be easier than I thought. I had the following file:

# build_info.rs
#![allow(unused_variables)]

include!(concat!(env!("OUT_DIR"), "/built.rs"));

However it still produced errors, and it blamed the errors on built.rs instead of build_info.rs. It turns out that allow(unused_variables) is the wrong attribute to use for const warnings, and instead using allow(dead_code) will silence them.

# build_info.rs
#![allow(dead_code)]

include!(concat!(env!("OUT_DIR"), "/built.rs"));

With that understanding, I'm completely fine with the way things work now. If anything I'd suggest a note in the documentation.

[lukaslueg]

I'm closing this for now, please re-open is this is still a problem