Orly?

So please explain!

$ perl -Mstrict -wE 'my $str = "foobar"; say 1 if $str =~ /{,3}/; say 
+$]'
5.028002
$
[download]

(Update perl version added)

update

>perl -Mstrict -wE "my $str = 'foobar'; say 1 if $str =~ /{,3}/; say $
+],':',$^O"
5.032001:MSWin32
[download]

I would guess there's a special case when the brace is the first character in the regex.

$ perl -wE 'say $]; say "Match literal" if "{,3}" =~ m<{,3}> && "x" !~
+ m<{,3}>;'
5.030001
Match literal

$ perl -wE 'say $]; say "Match space" if " {,3}" =~ m< {,3}> && "x" !~
+ m< {,3}>;'
Unescaped left brace in regex is illegal here in regex; marked by <-- 
+HERE in m/ { <-- HERE ,3}/ at -e line 1.
[download]

What's happening is that the space must be repeated.

 $  perl -wE 'say $]; say "Match space" if "   " =~ m< {0,3}>' 
 5.028002

Match space
$
[download]

Your error is thrown because {,3} is illegal as quantifier for Perl <5.34

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}