/usr/share/perl5/MouseX/ is in libmousex-getopt-perl 0.36-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/MouseX/Getopt/
/usr/share/perl5/MouseX/Getopt.pm
/usr/share/perl5/MouseX/Getopt/Basic.pm
/usr/share/perl5/MouseX/Getopt/Dashes.pm
/usr/share/perl5/MouseX/Getopt/GLD.pm
/usr/share/perl5/MouseX/Getopt/Meta/
/usr/share/perl5/MouseX/Getopt/Meta/Attribute/
/usr/share/perl5/MouseX/Getopt/Meta/Attribute.pm
/usr/share/perl5/MouseX/Getopt/Meta/Attribute/NoGetopt.pm
/usr/share/perl5/MouseX/Getopt/Meta/Attribute/Trait/
/usr/share/perl5/MouseX/Getopt/Meta/Attribute/Trait.pm
/usr/share/perl5/MouseX/Getopt/Meta/Attribute/Trait/NoGetopt.pm
/usr/share/perl5/MouseX/Getopt/OptionTypeMap.pm
/usr/share/perl5/MouseX/Getopt/Strict.pm