added some more information to an error message.

docs/changelog/7.x.x.txt

@@ -16,6 +16,8 @@
  - fixed: Donation: Add to Cart still visible in Thank You Message screen
  - optimized PurgeOldInboxMessages workflow
  - fixed: Calendar: Reorder Events in Week View Broken
+ - Added more information about workflow instance errors, so we can debug without having 
+   to watch SPECTRE's debug output.
 
 7.5.15
  - fixed: Colorpicker window would not open (Martin Kamerbeek / Oqapi)

lib/WebGUI/Workflow/Instance.pm

@@ -330,7 +330,9 @@ sub run {
 	if ($class && $method) {
         $object = eval { WebGUI::Pluggable::instanciate($class, $method, [$self->session, $params]) };
         if ($@) {
-			$self->session->errorHandler->error($@);
+			$self->session->errorHandler->error(
+                            q{Error on workflow instance '} . $self->getId . q{': }. $@
+                        );
 			$self->set({lastStatus=>"error"}, 1);
 			return "error";
         }