anchor.diff:      then findPaketDependenciesDir projDir [] |> Some
       else None
   
  -let private tryGetPaketRefNameAndDir paketDir (filter: string->bool) (refLine: string) =
  -    if filter refLine then
  -        let parts = refLine.Split(',')
  +let private tryGetPaketRefNameAndDir paketDir (filterPackage: string->bool) (refLine: string) =
  +    let parts = refLine.Split(',')
  +    if filterPackage parts.[0] then
           let refName, refGroup =
               if parts.Length = 4 then
                   match parts.[3].ToLower() with
  
positive.code:     match paketDir with
      | Some paketDir ->
          readPaketProjectRefLines targetFramework projFile
          |> Seq.choose (tryGetPaketRefNameAndDir paketDir (fun l -> l.StartsWith("Fable.Core")))
          |> Seq.tryHead
          |> Option.map (fun (_, corePkgDir) -> IO.Path.Combine(corePkgDir, "fable-core"))
      | None -> None
  
negative.code:             else None
          | None -> None
  
  let isSystemPackage (pkgName: string) =
      pkgName.StartsWith("Microsoft.")
          || pkgName.StartsWith("runtime.")
          || pkgName.StartsWith("System.")
          || pkgName = "FSharp.Core"
          || pkgName = "Fable.Core"
  
  let tryGetPaketRef paketDir (targetFramework: TargetFramework) (refLine: string): PaketRef option =
      tryGetPaketRefNameAndDir paketDir (isSystemPackage >> not) refLine
      |> Option.map (fun (refName, pkgDir) ->
          let fableProj = IO.Path.Combine(pkgDir, "fable", refName + ".fsproj")
          if File.Exists(fableProj) then
  