arplookup() in if_arp.c sometimes spews this message

    "arplookup: unable to enter address for %s (%s)"

and i thought i understood what triggered it, but apparently i'm
wrong.  or...i'm not the net.hacker i thought i was.

can someone please describe a packet or sequence of packets (i imagine
two at most) which will trigger this message?  i can manufacture
packets quite easily using bpf (except the ethernet source address),
but can't get this code sequence to trigger.

-- 
|-----< "CODE WARRIOR" >-----|
codewarrior@daemon.org             * "ah!  i see you have the internet
twofsonet@graffiti.com (Andrew Brown)                that goes *ping*!"
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