`cabal repl` load modules (C-c C-L) with `-Wx-partial` wants to add `{-# LANGUAGE Data #-}` for every occurrence of `head` and `tail`

[amcphail]

When loading a file in emacs, every occurrence of the functions head and tail trigger a question in the command buffer to add {-# LANGUAGE Data #-} to the top of the source file. This is triggered by the warning [-Wx-partial]

module Tmp where

test :: [Int] -> String
test [] = "empty"
test xs = show $ head xs

/src/Tmp.hs:5:18-21: warning: [GHC-63394] [-Wx-partial] …
    In the use of ‘head’
    (imported from Prelude, but defined in GHC.List):
    "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
  |
src/Tmp.hs:5:18-21: warning: [GHC-63394] [-Wx-partial] …
    In the use of ‘head’
    (imported from Prelude, but defined in GHC.List):
    "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."

|

ghc --version
The Glorious Glasgow Haskell Compilation System, version 9.8.2

$ cabal --version
cabal-install version 3.16.1.0
compiled using version 3.16.1.0 of the Cabal library (in-tree)

$ emacs --version
GNU Emacs 28.2
Copyright (C) 2022 Free Software Foundation, Inc.
GNU Emacs comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of GNU Emacs
under the terms of the GNU General Public License.
For more information about these matters, see the file named COPYING.

haskell-mode version is latest stable from melpa

[purcell]

haskell-mode version is latest stable from melpa

If you mean 17.5 from MELPA stable, that dates from Nov 2023 now, so please try with the latest snapshot version.

[amcphail]

Is this the correct repository:

(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)

If so, I still get the error.