The panic message you printed reports an error in
File::Basename, but you should also indicate the version
number of perl, and where you got it
perl -V
output would be valuable.
As others have said, the function XMLin is not part of
the core perl, so it is very difficult for anyone to
reproduce the problem without more information.
Do you think you could reproduce the problem without XMLin?
(obviously, there must be some other code that you didn't reproduce in your post, right :-)