--- Isabelle2012-orig/src/Pure/General/sha1_polyml.ML	2012-05-20 19:34:33.000000000 +1000
+++ Isabelle2012/src/Pure/General/sha1_polyml.ML	2012-12-05 23:24:06.263793934 +1100
@@ -18,7 +18,7 @@
   in (op ^) (pairself hex_digit (Integer.div_mod (Char.ord c) 16)) end
 
 val lib_path =
-  ("$ML_HOME/" ^ (if ML_System.platform_is_cygwin then "sha1.dll" else "libsha1.so"))
+  ("$SHA1_HOME/" ^ (if ML_System.platform_is_cygwin then "sha1.dll" else "libsha1.so"))
   |> Path.explode;
 
 fun digest_external str =