https://www.reddit.com/r/xmonad/comments/hlektm/installing_xmonad_with_ghcup_and_cabal/
cabal install xmonad cabal install –lib xmonad xmonad-contrib # make sure you also install xmonad as a lib so it compiles, not actually sure how to install the executable AND the lib #optionally you can install xmobar(and theoretically taffybar) using: cabal install -f with_xft -f with_xpm xmobar # because they default to false! See other options in .cabal/packages/xmobar/…tar.gz
Update: this no longer works for xmonad for me, and I don’t have the smarts or patience to understand what cabal-install is doing. Following the instructions to just clone xmonad + xmonad-contrib and use stack worked just fine.