anchor.diff:      | CCNet
       | Jenkins
       | Travis
  +    | AppVeyor
       | LocalBuild
   
   /// The trace mode option.
  
positive.code: /// [omit]
  let ccBuildLabel = environVar "CCNETLABEL"
  
  /// The current build server
  let buildServer = 
      if hasBuildParam "jenkins_home" then Jenkins
      elif not (isNullOrEmpty tcBuildNumber) then TeamCity
      elif not (isNullOrEmpty ccBuildLabel) then CCNet
      elif not (isNullOrEmpty travisBuildNumber) then Travis
      else LocalBuild
  
  /// The current build version as detected from the current build server.
  
negative.code:     | TeamCity -> getVersion tcBuildNumber
      | CCNet -> getVersion ccBuildLabel
      | Travis -> getVersion travisBuildNumber
      | AppVeyor -> getVersion appVeyorBuildNumber
      | LocalBuild -> getVersion localBuildLabel
  
  /// Is true when the current build is a local build.
  