anchor.diff:  let quickStrategy resolver sourceExplorer state selections = asyncSeq {
     let unresolved =
       breadthFirst selections state.Root
  -    |> Seq.sortBy (snd >> All >> simplify >> Constraint.chanceOfSuccess)
  +    |> Seq.sortByDescending (snd >> All >> simplify >> Constraint.chanceOfSuccess)
   
     for (p, cs) in unresolved do
       yield!
  
positive.code:       |> Result.Error
  }
  
  let resolutionManager (sourceExplorer : ISourceExplorer) : MailboxProcessor<ResolutionRequest> =
    MailboxProcessor.Start(fun inbox -> async {
      let mutable unresolvableCores : Map<Set<PackageConstraint>, SearchStrategyError> = Map.empty
      let mutable underconstraintDeps : Set<PackageConstraint> = Set.empty
      let mutable world : Map<PackageConstraint, Set<Set<PackageConstraint>>> = Map.empty
  
      let findBadCores (constraints : Constraints) =
        unresolvableCores
          |> Map.toSeq
  
negative.code:     Locations = manifest.Locations
    }
  
    let resolver = resolutionManager context
  
    let prefetcher = Prefetcher (context.SourceExplorer, 10)
  
  