Major Description
UDFFinder doesn't look into POCast so it will miss LoadFunc used by POCast for lineage. We could see "class not found" exception in some cases. Here is a sample script:
a = load '1.txt' using CustomLoader() as (a0, a1, a2);
b = group a by a0;
c = foreach b generate flatten(a);
d = order c by a0;
e = foreach d generate(a1+a2); -- use lineage
dump e;