nowadays in a tree we have the luatex package 0.70.1 and 0.70.1-r1 versions. both of them has RDEPEND on the >=app-text/poppler-0.12.3-r3[xpdf-headers(+)], but latter has no more xpdf-headers flag! (and of couse it can't be enabled)
Please read up on use defaults. http://dev.gentoo.org/~ulm/pms/4/pms.html#x1-830009.2.5
*** Bug 432820 has been marked as a duplicate of this bug. ***