Q:\>perl -MMoose -e "package Moo;use Moose; has 'foo' => (is => 'ro', isa => 'Int'); no Moose; package main; my $bar = Moo->new({foo => 'boom'});"
Attribute (foo) does not pass the type constraint because: Validation failed for 'Int' failed with value boom at g:/Systeme/tools/pe
rl-5.10.0/perl/site/lib/Moose/Meta/Attribute.pm line 774
        Moose::Meta::Attribute::_coerce_and_verify('Moose::Meta::Attribute=HASH(0x190c5f4)', 'boom', 'Moo=HASH(0x190c934)') called a
t g:/Systeme/tools/perl-5.10.0/perl/site/lib/Moose/Meta/Attribute.pm line 428
        Moose::Meta::Attribute::initialize_instance_slot('Moose::Meta::Attribute=HASH(0x190c5f4)', 'Moose::Meta::Instance=HASH(0x187
145c)', 'Moo=HASH(0x190c934)', 'HASH(0x3ea354)') called at g:/Systeme/tools/perl-5.10.0/perl/site/lib/Class/MOP/Class.pm line 365
        Class::MOP::Class::_construct_instance('Moose::Meta::Class=HASH(0x187104c)', 'HASH(0x3ea354)') called at g:/Systeme/tools/pe
rl-5.10.0/perl/site/lib/Class/MOP/Class.pm line 352
        Class::MOP::Class::new_object('Moose::Meta::Class=HASH(0x187104c)', 'HASH(0x3ea354)') called at g:/Systeme/tools/perl-5.10.0
/perl/site/lib/Moose/Meta/Class.pm line 205
        Moose::Meta::Class::new_object('Moose::Meta::Class=HASH(0x187104c)', 'HASH(0x3ea354)') called at g:/Systeme/tools/perl-5.10.
0/perl/site/lib/Moose/Object.pm line 25
        Moose::Object::new('Moo', 'HASH(0x12ca3ec)') called at -e line 1