A better solution would probably (Ignoring prebuilts like log4perl that solve this problem) to define your own "logging/error/warn" func that you can just turn off and on. Observe:

sub my_warn_of_god(@)
{
  if( $Main::Verbosity::Is::Double::PLus::Good )
  {
    print @_;
  }
}

#stuff
my_warn_of_god "Some stuff I want to see if debug";
#more stuff
my_warn_of_god "Other stuff";
#yet more stuff
[download]

This way you A) don't have to mess about with source filtering (which I don't trust..), and B) you don't have to do odd things like disabling push.