This I like ... for Laurent Etiemble, even line precise error reporting is not enough, so he has made some improvements to display the actual text that is in error. Details in his blog. It looks like:
This is certainly something that could show up in Tapestry 3.1 (either by duplicating Laurent's work, or getting him to properly donate it). Additionally, Geoff has talked about some kind of hook that would make the stack trace clickable links ... clicking the links would open the correct file inside Eclipse.