error[E0530]: match bindings cannot shadow unit variants
  --> $DIR/issue-27033.rs:4:9
   |
LL |         None @ _ => {}
   |         ^^^^ cannot be named the same as a unit variant
   | 
  ::: $SRC_DIR/libstd/prelude/v1.rs:LL:COL
   |
LL | pub use crate::option::Option::{self, None, Some};
   |                                       ---- the unit variant `None` is defined here

error[E0530]: match bindings cannot shadow constants
  --> $DIR/issue-27033.rs:8:9
   |
LL |     const C: u8 = 1;
   |     ---------------- the constant `C` is defined here
LL |     match 1 {
LL |         C @ 2 => {
   |         ^ cannot be named the same as a constant

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0530`.