Actually it has nothing to with <$a>, and this triggers it as well:
m: ' ' ~~ m:s/ /;
OUTPUT«===SORRY!=== Error while compiling Null regex not allowedat
:1--> ' ' ~~ m:s/ ⏏/;»
If this is indeed a bug, this should probably be renamed.
https://design.perl6.org/S05.html Reading this again, it seems that leading
whitespace is ignored. It says:
"The new :s (:sigspace) modifier causes certain whitespace sequences to be
considered "significant"; they are replaced by a whitespace matching rule,
<.ws>. Only whitespace sequences immed
# New Ticket Created by Samantha McVey
# Please include the string: [perl #130045]
# in the subject line of all future correspondence about this issue.
# https://rt.perl.org/Ticket/Display.html?id=130045 >
Expected result:
m: my $b = 'a b c'; $b ~~ s:ss/a /space/; say $b
OU
