error: Undefined Behavior: memory access failed: ALLOC has been freed, so this pointer is dangling
  --> tests/fail/dangling_pointers/dangling_primitive.rs:LL:CC
   |
LL |         dbg!(*ptr);
   |         ^^^^^^^^^^ 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_primitive.rs:LL:CC
   |
LL |         let x = 0usize; // This line should appear in the helps
   |             ^
help: ALLOC was deallocated here:
  --> tests/fail/dangling_pointers/dangling_primitive.rs:LL:CC
   |
LL |     };
   |     ^
   = note: BACKTRACE (of the first span):
   = note: inside `main` at RUSTLIB/std/src/macros.rs:LL:CC
   = note: this error originates in the macro `dbg` (in Nightly builds, run with -Z macro-backtrace for more info)

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

error: aborting due to 1 previous error