error[E0601]: `main` function not found in crate `cfg_attr_cfg_2` --> $DIR/cfg-attr-cfg-2.rs:9:14 | LL | fn main() { } | ^ consider adding a `main` function to `$DIR/cfg-attr-cfg-2.rs` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0601`.