Packages built using the perl MakeMaker package will have a file named .packlist in them. Those files are useless, and (in some cases) have the additional problem of creating an architecture-specific directory name in an architecture-independent package.
They can be suppressed by adding the following to
find debian/pkg -type f -name .packlist -delete
or by telling MakeMaker to use vendor install dirs; consult a recent version of Perl policy. Perl 5.6.0-12 or higher supports this.