Perl::Version vs version confusion

Version numbers should be boring and modules such as version and Perl::Version should be boring too.

Yet they are confusing me.

examples/sort_version_confusion.pl

use strict;
use warnings;
use 5.010;

use Perl::Version;
use version;
say "Perl::Version: $Perl::Version::VERSION";
say "version:       $version::VERSION";

my @versions = ( '5.11', 'v5.11', '5.011', '5.11');

say '----';

my @sorted = sort { Perl::Version->new( $a ) <=> Perl::Version->new( $b ) } @versions;
for my $s (@sorted) {
    say $s;
}

say '----';

my @other = sort { version->parse( $a ) <=> version->parse( $b ) } @versions;
for my $s (@other) {
    say $s;
}

And the output

Perl::Version: 1.013
version:       0.9912
----
5.11
v5.11
5.011
5.11
----
v5.11
5.011
5.11
5.11

I am not yet sure which module is confused, but I am, for sure.

It seems that Perl::Version thinks that 5.11 and v5.11 are the same while version thinks they are different.

Not only that, but Perl::Version seems to thin 5.11 equals to 5.011. I am fairly sure that should not be the case.

examples/version_compare_confusion.pl

use strict;
use warnings;
use 5.010;

use Perl::Version;
use version;

say Perl::Version->new('5.11') == Perl::Version->new('v5.11');   # 1
say version->parse('5.11') == version->parse('v5.11');           #


say Perl::Version->new('5.011') == Perl::Version->new('v5.11');   # 1
say version->parse('5.011') == version->parse('v5.11');           # 1

say Perl::Version->new('5.011') == Perl::Version->new('5.11');   # 1
say version->parse('5.011') == version->parse('5.11');           # 0