include! does not expand derive behind #[cfg_attr]

[alexcrichton]

For example.this does not compile:

// bar.rs
#[cfg_attr(foo, derive(Clone))]
struct A(u32);

// foo.rs
include!("bar.rs");
fn main() {
    A(1).clone();
}

Compiled with rustc --cfg foo foo.rs this will fail with A not implementing Clone.

[durka]

dupe #22250?

[alexcrichton]

Probably, yeah.