$ perl -MDDS -le" Dump($_); print grep /stuff/, 1,2,3,stuff; Dump($_)"
$VAR1 = undef;
stuff
$VAR1 = undef;

$ perl -MDDS -le" Dump($_); warn print grep /stuff/, 1,2,3,stuff; Dump($_)"
$VAR1 = undef;
stuff
1 at -e line 1.
$VAR1 = undef;