anchor.diff:              let run action chnl =
                   Run(target,
                       async {
  -                        let! lastBuild = (fun ch -> GetResult(target, ch)) |> ctx.Db.PostAndAsyncReply
  -
  -                        let! willRebuild = needRebuild ctx target lastBuild
  -
  -                        if willRebuild then 
  +                        match true with
  +                        //match ctx.NeedRebuild target with
  +                        | true ->
                               let taskContext = newTaskContext ctx                           
                               do ctx.Logger.Log Command "Started %s as task %i" (getShortname target) taskContext.Ordinal
   
  
positive.code:             // result expression is...
              target
              |> locateRule ctx.Rules ctx.Options.ProjectRoot
              |> Option.bind actionFromRule
              |> function
                  | Some action ->
                      async {
  
negative.code:         Logger: ILogger
          RootLogger: ILogger
          Ordinal: int
          NeedRebuild: Target -> bool
      }
  
      /// Main type.
  