Bugs

I think that I shall never see
a subroutine that works for me
a macro or a zero test
that isn't just a rodent's nest
a string that doesn't always stray
and mix up bit's in wild array
a process with re-entrant flair
that isn't just a looping snair
routines whose timings are not slain
when interrupts begin to rain
maybe god can make a tree
but bugs are made by guys like me!