message: Update tokio-trace-macros to work with latest tokio-trace
diff: -#[macro_use]
  extern crate tokio_trace;
  /// Alias of `dbg!` for avoiding conflicts with the `std::dbg!` macro.
  @@ -28,31 +27,24 @@ macro_rules! trace_dbg {
  macro_rules! dbg {
  (target: $target:expr, level: $level:expr, $ex:expr) => {
  {
  - #[allow(unused_imports)]
  use tokio_trace::{callsite, Id, Subscriber, Event, field::{debug, Value}};
  use tokio_trace::callsite::Callsite;
  - let callsite = callsite! {@
  + let callsite = callsite! {
  name: concat!("event:trace_dbg(", stringify!($ex), ")"),
  target: $target,
  level: $level,
  - fields: &[stringify!($ex)]
  + fields: $ex
  };
  - let interest = callsite.interest();
  let val = $ex;
  - if interest.is_never() {
  - val
  - } else {
  + if is_enabled!(callsite) {
  let meta = callsite.metadata();
  - let mut event = Event::new(interest, meta);
  - if !event.is_disabled() {
  + let fields = meta.fields();
  let key = meta.fields().into_iter().next()
  .expect("trace_dbg event must have one field");
  - event.record(&key, &debug(val));
  + Event::observe(meta, &fields.value_set(&[(&key, Some(&debug(&val) as &Value))]));
  }
  - drop(event);
  val
  }
  - }
  };
  (level: $level:expr, $ex:expr) => {
  dbg!(target: module_path!(), level: $level, $ex)
  