--- /dev/null
+#!perl
+package Point;
+use Mouse;
+
+# extra 'unknown_attr' is supplied (WARN)
+has 'x' => (isa => 'Int', is => 'rw', required => 1, unknown_attr => 1);
+
+# mandatory 'is' is not supplied (WARN)
+has 'y' => (isa => 'Int', required => 1);
+
+sub clear {
+ my $self = shift;
+ $self->x(0);
+ $self->y(0);
+}
+
+__PACKAGE__->meta->make_immutable(strict_constructor => 1);
+
+package main;
+
+# extra 'z' is supplied (FATAL)
+my $point1 = Point->new(x => 5, y => 7, z => 9);