Running 5.00502 I got the same thing. I looked a little further into it out of curiosity. Dumper does an odd thing if it gets something that's not a reference: it makes it a reference and tries again. This is the problem right here. A slightly different approach:

my @comps;
$comps[10] = "foo bar";

my $foo = \$comps[0];
my $bar = \$comps[5];
my $baz = \$comps[10];

print "$foo $bar $baz\n";
__END__
UNKNOWN(0x813e940) UNKNOWN(0x813eac8) SCALAR(0x80c84b4)
Attempt to free unreferenced scalar.
Attempt to free unreferenced scalar.
Attempt to free unreferenced scalar.
Attempt to free unreferenced scalar.
Segmentation fault (core dumped)
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Dumper is trying to take a reference to an undefined value here, and that's apparently not something the 5.005 series likes too much. I'm not sure at all what's causing the core dump. If I simply dump @comps the first time and exit, it prints a bunch of "Attempt to free unreferenced scalar" messages but doesn't core dump. If I remove the Dumper line too, it works just fine.

This is a problem both with perl and with Data::Dumper, and I suspect a bug report should go to both. 5.005* loathes references to undef and Dumper makes references to undef.

local $_ = "0A72656B636148206C72655020726568746F6E41207473754A";
while(s/..$//) { print chr(hex($&)) }
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