src/Tools/Code/code_scala.ML

 val setup =
   Code_Target.add_target
     (target, { serializer = isar_serializer, literals = literals,
       check = { env_var = "SCALA_HOME", make_destination = I,
         make_command = fn scala_home => fn p => fn _ =>
-          Path.implode (Path.append (Path.explode scala_home) (Path.explode "bin/scalac")) ^ " *.scala" } })
+          "export JAVA_OPTS='-Xms128m -Xmx512m -Xss2m' && "
+            ^ Path.implode (Path.append (Path.explode scala_home) (Path.explode "bin/scalac")) ^ " *.scala" } })
   #> Code_Target.add_syntax_tyco target "fun"
      (SOME (2, fn print_typ => fn fxy => fn [ty1, ty2] =>
         brackify_infix (1, R) fxy (
           print_typ BR ty1 (*product type vs. tupled arguments!*),
           str "=>",