anchor.diff:      let wsDir = Env.GetFolder Env.Folder.Workspace
   
       let switchToBranch (branch : string option) (repo : Repository) =
  -        let br = match branch with
  -                 | None -> repo.Branch
  -                 | Some x -> x
  -        IoHelpers.DisplayInfo repo.Name
  -        Tools.Vcs.Checkout wsDir repo br |> Exec.PrintOutput
  +        async {
  +            let br = match branch with
  +                     | None -> repo.Branch
  +                     | Some x -> x
  +            IoHelpers.DisplayInfo repo.Name
  +            let res = Tools.Vcs.Checkout wsDir repo br |> Exec.PrintOutput
  +            return res
  +        }
   
       match branchInfo.Branch with
       | Some x -> let branch = (x = graph.MasterRepository.Branch) ? (None, Some x)
  -                let res1 = switchToBranch branch graph.MasterRepository
  +                let res1 = switchToBranch branch graph.MasterRepository |> Async.RunSynchronously
                   let graph = Configuration.LoadAnthology() |> Graph.from
  -                let res2 = graph.Repositories |> Seq.filter (fun x -> x.IsCloned) |> Seq.map (switchToBranch branch)
  +                let res2 = graph.Repositories |> Seq.filter (fun x -> x.IsCloned)
  +                                              |> Threading.ParExec (switchToBranch branch)
                   let res = res1 |> Seq.singleton |> Seq.append res2
                   if res |> Seq.exists (fun x -> x.ResultCode <> 0) then
                       printfn "WARNING: failed to checkout some repositories"
  
positive.code:     convertInfo |> index
      if convertInfo.Check |> not then
          convertInfo |> convert
          
  
  let CheckMinVersion () =
      try
  
negative.code:     // checkout each repository now
      let graph = Configuration.LoadAnthology () |> Graph.from
      let repos = graph.Repositories
      let branchResults = repos |> Seq.filter (fun x -> x.IsCloned)
                                |> Threading.ParExec (checkoutRepo wsDir checkoutInfo.Version)
      branchResults |> Exec.CheckMultipleResponseCode
  
  