error: Undefined Behavior: constructing invalid value: wrong trait in wide pointer vtable: expected `Trait<u32>`, but encountered `Trait<i32>`
  --> tests/fail/validity/wrong-dyn-trait-generic.rs:LL:CC
   |
LL |     let _y: *const dyn Trait<u32> = unsafe { mem::transmute(x) };
   |                                              ^^^^^^^^^^^^^^^^^ Undefined Behavior occurred here
   |
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
   = note: BACKTRACE:
   = note: inside `main` at tests/fail/validity/wrong-dyn-trait-generic.rs:LL:CC

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to 1 previous error