src/Pure/General/mercurial.scala

       filter: List[String] = Nil,
       rev: String = ""
     ): Unit = {
       require(ssh == SSH.Local, "local repository required")
 
-      Isabelle_System.with_tmp_dir("rsync") { tmp_dir =>
+      Isabelle_System.with_tmp_dir("sync") { tmp_dir =>
         val (options, source) =
           if (rev.isEmpty) {
             val exclude_path = tmp_dir + Path.explode("exclude")
             val exclude = status(options = "--unknown --ignored --no-status")
             File.write(exclude_path, cat_lines((".hg" :: exclude).map("/" + _)))