better debugging for duff order_by

diff --git a/lib/SQL/Abstract/Converter.pm b/lib/SQL/Abstract/Converter.pm
index c6480e0..5e6f0cb 100644 (file)
--- a/lib/SQL/Abstract/Converter.pm
+++ b/lib/SQL/Abstract/Converter.pm
@@ -592,7 +592,7 @@ sub _order_by_to_dq {
         $nulls = $arg->{$key};
         die "invalid value for -nulls" unless $nulls =~ /^(?:first|last)$/i;
       } else {
-        die "invalid key in hash passed to _order_by_to_dq";
+        die "invalid key ${key} in hash passed to _order_by_to_dq";
       }
     }