One thing that seems strange is that you've specified a no-arguments prototype (the empty parentheses in the definition sub mySub() {...}), though you're then trying to call the routine with a parameter ( mySub("hello world") ) ...

Normally, this would throw a "Too many arguments for..." error, but presumably the error message doesn't show up due to the eval. Have you checked $@?

Any reason to not just say sub mySub {...} ?