23:48 >perl -wE "my $s = ''; say 'match1' if 'abc' =~ /b/; say 'match2' if 'adc =~ /(?:$s)/;"
match1
match2

23:55 >perl -wE "my $s = ''; say 'match1' if 'abc' =~ /b/; say 'match2' if 'adc =~ /$s/;"
match1

23:56 >raku -e "my Str $s = ''; say 'match1' if 'abc' ~~ /b/; say 'match2' if 'adc' ~~ /$s/;"
match1
match2

23:56 >