I suspect you've got it the wrong way round:

$ perl -E 'say "$_ => $SIG{$_}" for sort {$a cmp $b} keys %SIG'
ABRT =>
ALRM =>
BUS =>
CHLD =>
CLD =>
CONT =>
FPE => IGNORE
HUP =>

...

UNUSED =>
URG =>
USR1 =>
USR2 =>
VTALRM =>
WINCH =>
XCPU =>
XFSZ =>
[download]

and

$ perl -MData::Dumper -E 'say "$_ => $SIG{$_}" for sort {$a cmp $b} ke
+ys %SIG'

#snip much the same as above, except for...

__WARN__ =>
[download]

I don't have Data::Dump::Streamer installed, so I didn't try that. This was using Perl 5.10.0 on Debian.