--- a/langtools/src/share/classes/com/sun/tools/sjavac/Util.java	Wed Aug 13 15:47:58 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/sjavac/Util.java	Thu Aug 14 13:05:49 2014 +0200
@@ -62,7 +62,8 @@
 
     public static String justPackageName(String pkgName) {
         int c = pkgName.indexOf(":");
-        assert(c != -1);
+        if (c == -1)
+            throw new IllegalArgumentException("Expected ':' in package name (" + pkgName + ")");
         return pkgName.substring(c+1);
     }