http://www.perlmonks.org?node_id=449887


in reply to Re^3: starting a script when a file appears in a directory
in thread starting a script when a file appears in a directory

I must say though that the errors that it throws get a little confusing because it has a lot of xs code in it.
I must say that I don't know much about the subject matter being actually discussed here. However what I would tend to disagree is the claim above, for out of my (possibly limited) experience I don't see any explicit relation between "having a lot of XS code" and "throwing confusing erros".