On my amd64, XPDF wouldn't install. I noticed its configure complained that X / Motif wasn't installed, and so it could install various tools but NOT xpdf. This was from 3.0-r2. Please make xpdf depend on openmotif. After merging openmotif, xpdf merged properly.
openmotif is an optional dependency because you can built xpdf without it. the binary won't be built then, but some other tools
This isn't painfully obvious, especially for those of us who never USE=motif Perhaps some einfo, and some ebeeping and esleeping would get others' attention when this happens to them?