Attempting to install Xmonad - package hidden

Question

Probably just a big case of PICNIC, but when I tried to install Xmonad, I get errors stating

Could not load module ‘XMonad’
It is a member of the hidden package ‘xmonad-0.15’.
You can run ‘:set -package xmonad’ to expose it.
(Note: this unloads all the modules in the current scope.)
Locations searched:
  XMonad.hs
  XMonad.lhs
  XMonad.hsig
  XMonad.lhsig

How do I make these errors go away? Did I forget any steps? etc.

I installed Haskell and Xmonad via:

ghcup install
ghcup set
ghcup install-cabal
cabal new-update
cabal new-install cabal-install
cabal new-install xmonad
cabal new-install xmonad-contrib --lib
# Other possibly relevant info
ghc-pkg list # does not show xmonad or -contrib
ghc --version # 8.6.3
cabal --version # 2.4.1.0
xmonad --version # 0.15

scifisamurai · Answer 1 · 2020-02-16T01:11:22.553

Not sure if this will help you but I was receiving a similar error when trying to recompile xmonad on OS X:

$ xmonad --recompile
XMonad will use ghc to recompile, because "/Users/scifisamurai/.xmonad/build" does not exist.
Error detected while loading xmonad configuration file: /Users/scifisamurai/.xmonad/xmonad.hs
Loaded package environment from /Users/scifisamurai/.ghc/x86_64-darwin-8.6.5/environments/default

xmonad.hs:10:1: error:
    Could not load module ‘XMonad’
    It is a member of the hidden package ‘xmonad-0.15’.
    You can run ‘:set -package xmonad’ to expose it.
    (Note: this unloads all the modules in the current scope.)
    Use -v to see a list of the files searched for.
   |
10 | import XMonad
   | ^^^^^^^^^^^^^

xmonad.hs:20:1: error:
    Could not load module ‘XMonad.StackSet’
    It is a member of the hidden package ‘xmonad-0.15’.
    You can run ‘:set -package xmonad’ to expose it.
    (Note: this unloads all the modules in the current scope.)
    Use -v to see a list of the files searched for.
   |
20 | import qualified XMonad.StackSet as W
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Please check the file for errors.

I am running cabal version 3.0.0 though. However, I'm also using new-install.

The fix for me was adding --lib to the install command as mentioned here (though they're just using cabal install rather than cabal new-install): https://github.com/xmonad/xmonad/issues/199#issue-490757289

LIBRARY_PATH=/opt/X11/lib:$LIBRARY_PATH cabal new-install --lib xmonad xmonad-contrib

Then trying to recompile again:

$ xmonad --recompile
XMonad will use ghc to recompile, because "/Users/scifisamurai/.xmonad/build" does not exist.
XMonad recompilation process exited with success!

Hope that helps someone.

Side notes:

I'm also not seeing xmonad or xmonad-contrib listed in the output of ghc-pkg list. There is some useful information on that here: https://github.com/haskell/cabal/issues/6262#issuecomment-541124411 which explains why that's happening and to look for the library in the package.db which did work for me:

$ ghc-pkg list -f ~/.cabal/store/ghc-8.6.5/package.db|egrep 'X11|xmonad'
    X11-1.9.1
    xmonad-0.15
    xmonad-contrib-0.16

I'm setting LIBRARY_PATH in the above command since X11 failed to build on OS X when I tried to build xmonad initially a while ago and that was the fix as per: https://github.com/xmonad/X11/issues/24#issuecomment-47996753

It may not be needed anymore.

In my Arch Linux VM, I use pacman to install xmonad which doesn't have the above issues. If you're using Linux I would think there would be a similar way to install this using your package manager. That being said though cabal should work ...

Attempting to install Xmonad - package hidden

1 Answers1