message: Pointers must be valid, even pointers to zsts
diff: @@ -145,7 +145,7 @@ pub fn eval_main<'a, 'tcx: 'a>(
  main_instance,
  main_mir.span,
  main_mir,
  - Place::undef(),
  + Place::from_primval_ptr(PrimVal::Bytes(1).into(), ty::layout::Align::from_bytes(1, 1).unwrap()),
  StackPopCleanup::None,
  )?;
  @@ -177,6 +177,16 @@ pub fn eval_main<'a, 'tcx: 'a>(
  Err(mut e) => {
  ecx.tcx.sess.err(&e.to_string());
  ecx.report(&mut e, true, None);
  + for (i, frame) in ecx.stack().iter().enumerate() {
  + trace!("-------------------");
  + trace!("Frame {}", i);
  + trace!(" return: {:#?}", frame.return_place);
  + for (i, local) in frame.locals.iter().enumerate() {
  + if let Some(local) = local {
  + trace!(" local {}: {:?}", i, local);
  + }
  + }
  + }
  }
  }
  }
  