warning: any use of this value will cause an error
  --> $DIR/allowed-deny-by-default-lint.rs:7:16
   |
LL | const C: i32 = 1 / 0;
   | ------------   ^^^^^ attempt to divide `1_i32` by zero
   |
   = note: requested on the command line with `--force-warn const-err`
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800>

warning: 1 warning emitted

Future incompatibility report: Future breakage diagnostic:
warning: any use of this value will cause an error
  --> $DIR/allowed-deny-by-default-lint.rs:7:16
   |
LL | const C: i32 = 1 / 0;
   | ------------   ^^^^^ attempt to divide `1_i32` by zero
   |
   = note: requested on the command line with `--force-warn const-err`
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800>