Instructions for ArchLinux.

[alissa-tung]

This is not a bug, but I thought is missing somewhere.

Although ArchLinux had a patch on the default build scripts (enable -dynamic), there's still something worth mentioned on correspondence pages (ArchLinux Wiki, XMonad documents, etc.) that is
If you install XMonad via Pacman from the official repository, make sure you are using the dependencies of the package, especially GHC (/usr/bin/ghc), which can be done by a minor tweaked build script.
The current XMonad implementation encode the default compile command using the string "ghc", which is undecidable which to call (ghcup, nix-env, nix-shell or even more cursed).

[slotThe]

I think the general consensus is that we want users on Arch to build with stack or cabal instead of having to endure dynamically linked Haskell. The tutorial mentions something like this already but then again we do have instructions for Arch in INSTALL.md...

A PR for improving documentation for Arch would be welcome—some people insist on using pacman, after all

[mikenrafter]

Another solution would be to use nix.

Though, that may be overkill for most users.