/usr/lib/perl5/Mouse/Meta/ is in libmouse-perl 2.1.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/perl5/Mouse/Meta/Attribute.pm
/usr/lib/perl5/Mouse/Meta/Class.pm
/usr/lib/perl5/Mouse/Meta/Method/
/usr/lib/perl5/Mouse/Meta/Method.pm
/usr/lib/perl5/Mouse/Meta/Method/Accessor.pm
/usr/lib/perl5/Mouse/Meta/Method/Constructor.pm
/usr/lib/perl5/Mouse/Meta/Method/Delegation.pm
/usr/lib/perl5/Mouse/Meta/Method/Destructor.pm
/usr/lib/perl5/Mouse/Meta/Module.pm
/usr/lib/perl5/Mouse/Meta/Role/
/usr/lib/perl5/Mouse/Meta/Role.pm
/usr/lib/perl5/Mouse/Meta/Role/Application.pm
/usr/lib/perl5/Mouse/Meta/Role/Composite.pm
/usr/lib/perl5/Mouse/Meta/Role/Method.pm
/usr/lib/perl5/Mouse/Meta/TypeConstraint.pm