error: Undefined Behavior: constructing invalid value: encountered $HEX[ALLOC], but expected a vtable pointer --> $DIR/issue-miri-1112.rs:LL:CC | LL | let obj = std::mem::transmute::(obj); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered $HEX[ALLOC], but expected a vtable pointer | = 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 `FunnyPointer::from_data_ptr` at $DIR/issue-miri-1112.rs:LL:CC note: inside `main` at $DIR/issue-miri-1112.rs:LL:CC --> $DIR/issue-miri-1112.rs:LL:CC | LL | let _raw: &FunnyPointer = FunnyPointer::from_data_ptr(&hello, &meta as *const _); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace error: aborting due to previous error