haskell.packages.ghc8{107,84}.OneTuple: provide hashable

We need to manually simulate the following conditional in the cabal
file:

    if impl(ghc >=9.0)
      build-depends: ghc-prim

    else
      build-depends: hashable >=1.3.5.0 && <1.5

1 files changed, 5 insertions, 0 deletions

diff --git a/pkgs/development/haskell-modules/configuration-ghc-8.8.x.nix b/pkgs/development/haskell-modules/configuration-ghc-8.8.x.nix
index 9257ebb1a308..2db51bbbfc4e 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-8.8.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-8.8.x.nix
@@ -142,4 +142,9 @@ self: super: {
     # https://github.com/haskell/haskell-language-server/issues/2728
     hls-hlint-plugin = null;
   });
+
+  # OneTuple needs hashable instead of ghc-prim for GHC < 9
+  OneTuple = super.OneTuple.override {
+    ghc-prim = self.hashable;
+  };
 }