grunt should show full exception stack

I suggest grunt should be more helpful with user errors. I just did one (a stupid one) and it took my too long to figure out the problem, since grunts error message was just not giving me a good hint:
grunt> A = LOAD '/pigtestData.tsv' USING PigStorage(',') AS (user,age,cat);
grunt> B = FILTER A BY cat == 'book';
grunt> dump B;
For input string: "book"
Experts will see that I tried to use == instead of eq, however especially new users could get a little confused.
I see two chances add Error Number and descriptive texts (Oracle style) - this quite a lot of work, or for now I suggest to simply dump the full exception text.

At least for this early stage it would developers and users to find problems faster.