Unknown 'build_class', defaulting to 'Module::Build' and /usr/pkg/usr/pkg

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

I'm trying to pkgsrc Text::DHCPLeases and I end up with everything (including 
the packlist) being written to /usr/pkg/usr/pkg/lib/perl5/vendor_perl/5.8.0/ 
(note the double /usr/pkg, I had to look at the output three times before 
noticing).
The only warning I get is

Creating new 'Build' script for 'Text-DHCPLeases' version 'v0.7'
Unknown 'build_class', defaulting to 'Module::Build'

Is this a known issue?

My Makefile is

DISTNAME=       Text-DHCPLeases-v0.7
PKGNAME=        p5-${DISTNAME:C/-v/-/}
CATEGORIES=     net perl5
MASTER_SITES=   http://search.cpan.org/CPAN/authors/id/C/CV/CVICENTE/

MAINTAINER=     pkgsrc-users%NetBSD.org@localhost
HOMEPAGE=       http://search.cpan.org/~cvicente/${DISTNAME}
COMMENT=        Parse DHCP leases file from ISC dhcpd

PKG_DESTDIR_SUPPORT=    user-destdir

PERL5_PACKLIST=         auto/Text/DHCPLeases/.packlist

.include "../../lang/perl5/module.mk"
.include "../../mk/bsd.pkg.mk"

Thanks for any help.