$ perl-5.8.8 -e 'require 5.010; /1++/'
Nested quantifiers in regex; marked by <-- HERE in m/1++ <-- HERE / at -e line 1.

##</code><code>##

$ perl-5.8.8 -e 'use 5.010; /1++/'
Perl v5.10.0 required--this is only v5.8.8, stopped at -e line 1.
BEGIN failed--compilation aborted at -e line 1.