message: Remove format!
diff: @@ -95,7 +95,7 @@ impl<'a, 'cfg> Timings<'a, 'cfg> {
  (pkg_desc, targets)
  })
  .collect();
  - let start_str = format!("{}", humantime::format_rfc3339_seconds(SystemTime::now()));
  + let start_str = humantime::format_rfc3339_seconds(SystemTime::now()).to_string();
  let has_report = |what| {
  bcx.config
  .cli_unstable()
  