warning: this constant cannot be used
  --> $DIR/issue-43197.rs:18:5
   |
LL |     const X: u32 = 0-1;
   |     ^^^^^^^^^^^^^^^---^
   |                    |
   |                    attempt to subtract with overflow
   |
note: lint level defined here
  --> $DIR/issue-43197.rs:11:9
   |
LL | #![warn(const_err)]
   |         ^^^^^^^^^

warning: this constant cannot be used
  --> $DIR/issue-43197.rs:20:5
   |
LL |     const Y: u32 = foo(0-1);
   |     ^^^^^^^^^^^^^^^^^^^---^^
   |                        |
   |                        attempt to subtract with overflow

error[E0080]: referenced constant has errors
  --> $DIR/issue-43197.rs:22:26
   |
LL |     const Y: u32 = foo(0-1);
   |                        --- attempt to subtract with overflow
LL |     //~^ WARN this constant cannot be used
LL |     println!("{} {}", X, Y);
   |                          ^

error[E0080]: erroneous constant used
  --> $DIR/issue-43197.rs:22:26
   |
LL |     println!("{} {}", X, Y);
   |                          ^ referenced constant has errors

error[E0080]: referenced constant has errors
  --> $DIR/issue-43197.rs:22:23
   |
LL |     const X: u32 = 0-1;
   |                    --- attempt to subtract with overflow
...
LL |     println!("{} {}", X, Y);
   |                       ^

error[E0080]: erroneous constant used
  --> $DIR/issue-43197.rs:22:23
   |
LL |     println!("{} {}", X, Y);
   |                       ^ referenced constant has errors

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0080`.