dev-perl/PDL-2.4.0 depends on dev-perl/ExtUtils-MakeMaker but that is not accounted for in the dependency tree of dev-perl/PDL-2.4.0 ...or so i think...thanks! you all do a great job!
I'm going to out on a limb here and guess that you performed a depclean recently. The Short Answer: emerge dev-perl/ExtUtils-MakeMaker and you will be all set. The Long Answer: For a long time, MakeMaker was a part of the eclass for perl modules. This was to overcome a fault in the version of MakeMaker that was available for perl 5.6.1 users (which at one point in the not so distant past, was our only user base). However, the ebuild for 5.6.1 has since been adjusted to roll the MakeMaker fix into the ebuild itself, so the dependancy was removed. The version of MakeMaker that came with 5.8 was always good. However, if you had the new version installed via ebuild, and recently performed a depclean, MakeMaker was removed (since it was no longer marked as a dependancy of anything). The next version of perl 5.8.0, r-12, is currently in testing and finzalizes the elimination of this dependancy along with a safer way to emerge core perl modules without overwriting the ones that came with perl (so if they are unmerged, there is no harm). Back to the Short Answer: re-emerge dev-perl/ExtUtils-MakeMaker and you will be all set.
Marking as fixed since there has been no feedback in over a month. If this is still an issue, please reopen this bug.