             continue
           }
           // Short argument — add each character to options
-          for char in arg.substring(from: arg.index(after: arg.startIndex)).characters {
+          for char in arg[arg.index(after: arg.startIndex)...] {
             // Avoid inserting a false '--'
             if char == "-" {
               continue

    _ destPaths: [String],
    verbosity:   Int = 0
  ) -> Int32 {
    let workspace: NSWorkspace = NSWorkspace.shared()
    var success: Bool
    var ret:     Int32 = 0


      workspace.setIcon(
        nil,
        forFile: path,
        options: NSWorkspace.IconCreationOptions(rawValue: 0)
      )
      success = workspace.setIcon(
        icon,
        forFile: path,
        options: NSWorkspace.IconCreationOptions(rawValue: 0)
      )

      if !success {
