message: we did not need a &(||...) we can just add a & at use
diff: @@ -160,12 +160,12 @@ pub fn resolve_with_previous<'a, 'cfg>(
  );
  }
  - let keep = &(|p: &&'a PackageId| {
  + let keep = |p: &&'a PackageId| {
  !to_avoid_sources.contains(&p.source_id()) && match to_avoid {
  Some(set) => !set.contains(p),
  None => true,
  }
  - });
  + };
  // In the case where a previous instance of resolve is available, we
  // want to lock as many packages as possible to the previous version
  @@ -173,7 +173,7 @@ pub fn resolve_with_previous<'a, 'cfg>(
  let mut try_to_use = HashSet::new();
  if let Some(r) = previous {
  trace!("previous: {:?}", r);
  - register_previous_locks(ws, registry, r, keep);
  + register_previous_locks(ws, registry, r, &keep);
  // Everything in the previous lock file we want to keep is prioritized
  // in dependency selection if it comes up, aka we want to have
  @@ -535,7 +535,7 @@ fn register_previous_locks<'a>(
  // function let's put it to action. Take a look at the previous lockfile,
  // filter everything by this callback, and then shove everything else into
  // the registry as a locked dependency.
  - let keep = &(|id: &&'a PackageId| keep(id) && !avoid_locking.contains(id));
  + let keep = |id: &&'a PackageId| keep(id) && !avoid_locking.contains(id);
  for node in resolve.iter().filter(keep) {
  let deps = resolve
  