message: Reference issue 1763 in the comment.
diff: @@ -714,10 +714,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  if let Some((thread, callback)) = this.machine.threads.get_ready_callback() {
  (thread, callback)
  } else {
  - // get_ready_callback can return None if the computer's clock was
  - // shifted after calling the scheduler and before the call
  - // to get_ready_callback. In this case, just do nothing, which
  - // effectively just returns to the scheduler.
  + // get_ready_callback can return None if the computer's clock
  + // was shifted after calling the scheduler and before the call
  + // to get_ready_callback (see issue
  + // https://github.com/rust-lang/miri/issues/1763). In this case,
  + // just do nothing, which effectively just returns to the
  + // scheduler.
  return Ok(());
  };
  // This back-and-forth with `set_active_thread` is here because of two
  