Xmonad does not compile anymore

Though xmonad (v. 0.15-134) and xmonad-contrib (v. 0.16-114) seem uptodate, I can’t update it anymore since the last couple of months, as $ xmonad --recompile always crashes (working in Arch though).

Maybe there’s something wrong with their deps?

The only thing that comes to mind - without checking the PKGBUILD - is linux headers - but that is a long shot.