anchor.diff:  
       member this.HasCommit (gitPath : string) (revision : Revision) = async {
         let command =
  -        "git --no-pager --git-dir=" + gitPath +
  +        "git --no-pager -C " + gitPath +
           " log " + revision + " --pretty=format:'%H' -n0"
         let! result = runBash(command) |> Async.Catch
         return
  
positive.code:       do! (this :> IGit).FetchBranch repository branch
        let gitDir = repository
        let command =
          "git --no-pager --git-dir=" + gitDir +
          " log " + branch + " --pretty=format:'%H'"
        let! output = runBash(command)
        return
  
negative.code:   member this.LocalBranches (repository : String) = async {
      let gitDir = repository
      let command =
        "git --no-pager -C " + gitDir +
        " branch"
      let! output = runBash(command)
  
  