error: Undefined Behavior: in-bounds pointer arithmetic failed: ALLOC has been freed, so this pointer is dangling
  --> tests/fail/dangling_pointers/dangling_pointer_offset.rs:LL:CC
   |
LL |     let x = unsafe { p.offset(42) };
   |                      ^^^^^^^^^^^^ 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
help: ALLOC was allocated here:
  --> tests/fail/dangling_pointers/dangling_pointer_offset.rs:LL:CC
   |
LL |         let b = Box::new(42);
   |                 ^^^^^^^^^^^^
help: ALLOC was deallocated here:
  --> tests/fail/dangling_pointers/dangling_pointer_offset.rs:LL:CC
   |
LL |     };
   |     ^

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

error: aborting due to 1 previous error