src/Pure/Admin/build_history.scala

     /* synchronize Isabelle + AFP repositories */
 
     def sync(target: Path, accurate: Boolean = false,
       rev: String = "", afp_rev: String = "", afp: Boolean = false
     ): Unit = {
-      val context = Rsync.Context(progress, ssh = ssh, protect_args = protect_args)
+      val context = Rsync.Context(progress = progress, ssh = ssh, protect_args = protect_args)
       Sync.sync(ssh.options, context, target,
         thorough = accurate, preserve_jars = !accurate,
         rev = rev, afp_rev = afp_rev, afp_root = if (afp) afp_repos else None)
     }