error[E0601]: `main` function not found in crate `cfg_attr_cfg_2`
  --> $DIR/cfg-attr-cfg-2.rs:8:1
   |
LL | / #[cfg_attr(foo, cfg(bar))]
LL | | fn main() { }
   | |_____________^ consider adding a `main` function to `$DIR/cfg-attr-cfg-2.rs`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0601`.