Log Message:
Initial import of p5-XXX, which exports a function called XXX that you
can put just about anywhere in your Perl code to make it die with a YAML
dump of the arguments to its right.

The charm of XXX-debugging is that it is easy to type, rarely requires
parens and stands out visually so that you remember to remove it.

XXX.pm also exports WWW, YYY and ZZZ which do similar debugging things.