1 files changed, 7 insertions, 2 deletions
diff --git a/lib/sisu/develop/dp.rb b/lib/sisu/develop/dp.rb
index d5a72817..68f8c610 100644
--- a/lib/sisu/develop/dp.rb
+++ b/lib/sisu/develop/dp.rb
@@ -146,8 +146,13 @@ module SiSU_Param
         @@md=@md
       else @@md
       end
-      @@md.opt=@opt
-      @@md
+      begin
+        @@md.opt=@opt
+        @@md
+      rescue
+        SiSU_Utils::CodeMarker.new(__LINE__,__FILE__,:fuchsia).mark('has an existing option been selected?')
+        exit
+      end
     end
     class MdDefault
       def rights(author,date)