An alternative location could be ~/.cache/xmonad. yi - possibly via dyre - stores stuff in ~/.cache/yi.
Yes, I thought about it, but only putting the build files in a freedesktop conforming directory could be perhaps confusing, and I didn't wanted to change the configuration/source directory for backward compatibility reasons. Perhaps having the search order ["~/.config/xmonad", "~/.xmonad"] for configuration/source files could solve that issue. Looking at the 'XDG Base Directory Specification'[1], I don't know if the cache directory is the right one, because of: "... user-specific
non-essential <<< (cached) data should be written."
It's also not that clear what the difference is between $XDG_CACHE_HOME and $XDG_RUNTIME_DIR. There's also $XDG_DATA_HOME, which default value is "~/.local/share", which seems quite strange for user specific data. The XDG seems to be the kind of specification which might create more issues than it solves. [1] http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html