/usr/share/perl5/HTML/Widget/Constraint/ is in libhtml-widget-perl 1.11-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/HTML/Widget/Constraint/ASCII.pm
/usr/share/perl5/HTML/Widget/Constraint/All.pm
/usr/share/perl5/HTML/Widget/Constraint/AllOrNone.pm
/usr/share/perl5/HTML/Widget/Constraint/Any.pm
/usr/share/perl5/HTML/Widget/Constraint/Bool.pm
/usr/share/perl5/HTML/Widget/Constraint/Callback.pm
/usr/share/perl5/HTML/Widget/Constraint/CallbackOnce.pm
/usr/share/perl5/HTML/Widget/Constraint/Date.pm
/usr/share/perl5/HTML/Widget/Constraint/DateTime.pm
/usr/share/perl5/HTML/Widget/Constraint/DependOn.pm
/usr/share/perl5/HTML/Widget/Constraint/Email.pm
/usr/share/perl5/HTML/Widget/Constraint/Equal.pm
/usr/share/perl5/HTML/Widget/Constraint/HTTP.pm
/usr/share/perl5/HTML/Widget/Constraint/In.pm
/usr/share/perl5/HTML/Widget/Constraint/Integer.pm
/usr/share/perl5/HTML/Widget/Constraint/Length.pm
/usr/share/perl5/HTML/Widget/Constraint/Maybe.pm
/usr/share/perl5/HTML/Widget/Constraint/Number.pm
/usr/share/perl5/HTML/Widget/Constraint/Printable.pm
/usr/share/perl5/HTML/Widget/Constraint/Range.pm
/usr/share/perl5/HTML/Widget/Constraint/Regex.pm
/usr/share/perl5/HTML/Widget/Constraint/SingleValue.pm
/usr/share/perl5/HTML/Widget/Constraint/String.pm
/usr/share/perl5/HTML/Widget/Constraint/Time.pm