diff -r 90bb4cabe1e8 -r c5db368833b1 src/Pure/Tools/dump.scala
--- a/src/Pure/Tools/dump.scala	Sat Sep 22 13:22:43 2018 +0200
+++ b/src/Pure/Tools/dump.scala	Sat Sep 22 14:24:53 2018 +0200
@@ -270,6 +270,6 @@
               sessions = sessions))
         }
 
-      if (!ok) sys.exit(1)
+      if (!ok) sys.exit(2)
     })
 }