** Using WeBWorK **

Your problem does seem a bit unusual. The line in pg/lib/Parser/BOP/union.pm that is indicated as the error is "use strict", which should not cause an infinite loop. But that line is mainly for assistance in debugging, so you can safely comment it out. Try that and see if that helps. The other messages (about the copy method) are probably because the child that timed out is getting used for additional requests, and thinks that the parser code is set up while actually it isn't.

Davide