Can't build pandoc-crossref-bin

Thanks to your awesome project, I could automate building many AUR pkgs, but fore some reason pandoc-crossref-bin (https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=pandoc-crossref-bin) fails. Is something needed to be done in a pre-build script? Could you please look into it?