src/Pure/System/isabelle_system.scala

     bash("chown " + arg + " " + File.bash_path(path)).check
 
 
   /* directories */
 
-  def mkdirs(path: Path): Unit =
+  def make_directory(path: Path): Unit =
     if (!path.is_dir) {
       bash("perl -e \"use File::Path make_path; make_path('" + File.standard_path(path) + "');\"")
       if (!path.is_dir) error("Failed to create directory: " + quote(File.platform_path(path)))
     }
 

   /* tmp files */
 
   def isabelle_tmp_prefix(): JFile =
   {
     val path = Path.explode("$ISABELLE_TMP_PREFIX")
-    path.file.mkdirs  // low-level mkdirs
+    path.file.mkdirs  // low-level mkdirs to avoid recursion via Isabelle environment
     File.platform_file(path)
   }
 
   def tmp_file(name: String, ext: String = "", base_dir: JFile = isabelle_tmp_prefix()): JFile =
   {