$ perl5.12.5 -we'for my $k qw(a b) {$_=$k}'
$ perl5.14.0 -we'for my $k qw(a b) {$_=$k}'
Use of qw(...) as parentheses is deprecated at -e line 1.
$ perl5.16.3 -we'for my $k qw(a b) {$_=$k}'
Use of qw(...) as parentheses is deprecated at -e line 1.
$ $ perl5.18.0 -we'for my $k qw(a b) {$_=$k}'
syntax error at -e line 1, near "$k qw(a b)"
Execution of -e aborted due to compilation errors.