|Think about Loose Coupling|
Re^2: trouble with custom signal handlersby afoken (Abbot)
|on Apr 17, 2016 at 12:01 UTC||Need Help??|
Anything else that could de-register a signal handler?
Usually, signal handlers are set and unset by assigning to %SIG, so start looking for assignments to %SIG. A text search for "SIG" should be sufficient.
And the most obvious one: Search for the constant part of the error message ("received, but no signal handler set.") in the code.
A quick CPAN search reveals that the message may actually come from within perl, from the thread handling or the magic handling code. However, perldiag does not document this message. So, it looks to me like you have really messed up perl's internals.
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)