installing spamassassin on amd64 7.0

[steve%prd.co.uk@localhost (Steve Blinkhorn)]

Every time I have attempted to install spamassassin I have run into
difficulties with mutiple Perl modules either absent, nor not matching
the current version of Perl or some such.

Having recently re-equipped with amd64 7.0 machines it is time to try
again.   Whether from /usr/pkgsrc/mail/spamassassin or using
pkg_add -u -u I get essentially the same failure messages, e.g.:

# pkg_add -u -u spamassassin
pkg_add: Dependency of p5-BerkeleyDB-0.54 fulfilled by perl-5.20.1, but not by p erl-5.24.0
pkg_add: Dependency of p5-IO-Multiplex-1.13nb3 fulfilled by perl-5.20.1, but not by perl-5.24.0
pkg_add: Dependency of p5-Net-Server-2.007nb1 fulfilled by perl-5.20.1, but not by perl-5.24.0
pkg_add: Dependency of p5-Digest-SHA1-2.13nb6 fulfilled by perl-5.20.1, but not by perl-5.24.0
pkg_add: Dependency of p5-HTML-Tagset-3.20nb6 fulfilled by perl-5.20.1, but not by perl-5.24.0
pkg_add: Can't install dependency perl>=5.24.0
pkg_add: Can't install dependency p5-Business-ISBN-Data>=20140910.002
pkg_add: Can't install dependency p5-Business-ISBN-[0-9]*
pkg_add: Can't install dependency p5-URI-[0-9]*
pkg_add: Can't install dependency p5-HTML-Parser>=3.43
pkg_add: 1 package addition failed

Where am I going wrong?

-- 
Steve Blinkhorn <steve%prd.co.uk@localhost>