error: variable `X` should have a snake case name
  --> $DIR/expr_attr_paren_order.rs:17:17
   |
LL |             let X = 0;
   |                 ^ help: convert the identifier to snake case (notice the capitalization): `x`
   |
note: the lint level is defined here
  --> $DIR/expr_attr_paren_order.rs:15:37
   |
LL |     #[allow(non_snake_case)] #[deny(non_snake_case)] (
   |                                     ^^^^^^^^^^^^^^

error: aborting due to 1 previous error