You’re right! But at least warnings raises a red flag:

18:38 >perl -Mstrict -wE "foreach (my $RID) { say qq[\$RID = >$RID<]; 
+}"
Use of uninitialized value $RID in concatenation (.) or string at -e l
+ine 1.
$RID = ><

18:43 >
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I wasn’t expecting the loop to be entered at all, and Foreach Loops doesn’t seem to shed much light on the issue. But I’m guessing it’s the difference between a scalar undef and an empty list:

18:45 >perl -Mstrict -wE "foreach (my @RID) { say 'okay'; }"

18:46 >
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Seems the foreach is treating $RID as a list containing one element (with the value undef), as though it were foreach (my @RID = (undef)):.

18:46 >perl -Mstrict -wE "foreach (my @RID = (undef)) { say 'okay'; }"
okay

18:51 >
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Thanks for pointing this out!