in reply to
Entire project on CPAN -- including all modules
If they're not bundled in the same distribution (.tar.gz) file then you could put prerequisites in the Makefile.PL of each separate module. Since you said you use ExtUtils::MakeMaker, I've done that with:
#
# $Id: Makefile.PL 49 2009-05-31 13:15:34Z $
#
use ExtUtils::MakeMaker;
require v5.6.1;
WriteMakefile(
NAME => 'Module::Name',
VERSION_FROM => 'lib/Module/Name.pm',
LICENSE => 'artistic',
ABSTRACT_FROM => 'lib/Module/Name.pm',
AUTHOR => 'VinsWorldcom',
PREREQ_PM => {
Business::ISP::m1 => 1.00 # must be greater than ver 1
Business::ISP::m2 => 0 # version doesn't matter
},
);