Digest-MD5 installs its files into /usr/lib/site_perl/ instead of /usr/lib/perl5/site_perl/ this breaks the build of Digest-HMAC because it can't find MD5.pm . It don't know why it does that, as it is installed like all other perl-modules. Maybe it is a difference in the package.
*** This bug has been marked as a duplicate of 9067 ***