How to make Haskell-Mode for Emacs work (on GuixSD)?

[Mekeor Melire]

On GuixSD, with Guix, I installed the packages `emacs`, `haskell-mode`
and `cabal-install`. When I open a Haskell source file in Emacs, using
haskell-mode, and try load it using `haskell-process-load-file' (C-c
C-l), (having `interactive-haskell-mode' in `haskell-mode-hook',) I get
this error:

    Package has never been configured. Configuring with default flags.
    If this fails, please run configure manually.

    cabal: Use of GHC's environment variable GHC_PACKAGE_PATH is
    incompatible with Cabal. Use the flag --package-db to specify a
    package database (it can be used multiple times).

Is anyone able to use haskell-mode successfully? What am I missing?

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mekeor ~ EDD3 DFFA 76F6 11C0 145F 9A99 AC85 BAD8 A2F8 C868