The crash in "explain" looks very like this
But that bug is fixed in 184.108.40.206. You claim to be running
220.127.116.11, but I don't think you can be.
By the way... I don't understand the meaning of the
"OPT" messages, what is it complaining about?
It's not complaining about anything. When you use -explain,
you switch on two options: (a) optimizer tracing, which tells you where the
expressions have been rewritten by the optimizer for efficiency, and (b) a
display of the final expression tree after all the rewrites have been completed.
For example, it's telling you that ss:Cell[$start-col] was replaced with the
internal function call itemAt(ss:Cell, 5). This doesn't mean that there is
anything wrong with your code; on the contrary, it's good if you write your code
in a way that can be optimized. In this case the optimization allows Saxon to
directly select the 5th item in the input sequence, rather than scanning the
whole input sequence and testing each item to see if its position number is