Use cabal 3.8

builder/hspkg-builder.nix

@@ -53,7 +53,7 @@ let
       ||
         # These are the dependencies of `Cabal`
         !builtins.elem package.identifier.name
-          ["nix-tools" "alex" "happy" "hscolour" "Cabal" "bytestring" "aeson" "time"
+          ["nix-tools" "alex" "happy" "hscolour" "Cabal" "Cabal-syntax" "bytestring" "aeson" "time"
            "filepath" "base-compat-batteries" "base-compat" "unix" "directory" "transformers"
            "containers" "binary" "mtl" "text" "process" "parsec"];
 

lib/call-cabal-project-to-nix.nix

@@ -329,14 +329,14 @@ let
   # when `checkMaterialization` is set.
   dummy-ghc-data =
     let
-      materialized = ../materialized/dummy-ghc + "/${ghc.targetPrefix}${ghc.name}-${pkgs.stdenv.buildPlatform.system}";
+      materialized = ../materialized/dummy-ghc + "/${ghc.targetPrefix}${ghc.name}-${pkgs.stdenv.buildPlatform.system}"
+        + pkgs.lib.optionalString (builtins.compareVersions ghc.version "8.10" < 0 && ghc.targetPrefix == "" && builtins.compareVersions pkgs.lib.version "22.05" < 0) "-old";
     in pkgs.haskell-nix.materialize ({
       sha256 = null;
       sha256Arg = "sha256";
       materialized = if __pathExists materialized
         then materialized
-        else __trace ("WARNING: No materialized dummy-ghc-data for "
-            + "${ghc.targetPrefix}${ghc.name}-${pkgs.stdenv.buildPlatform.system}.")
+        else __trace "WARNING: No materialized dummy-ghc-data.  mkdir ${toString materialized}"
           null;
       reasonNotSafe = null;
     } // pkgs.lib.optionalAttrs (checkMaterialization != null) {

lib/ghcjs-project.nix

@@ -39,7 +39,7 @@
   if (builtins.compareVersions ghcjsVersion "8.10.0.0" >= 0)
   then pkgs.haskell-nix.tool compiler-nix-name "cabal" {
     index-state = pkgs.haskell-nix.internalHackageIndexState;
-    version = "3.6.2.0";
+    version = "3.8.1.0";
     materialized = ../materialized/ghcjs/cabal + "/${compiler-nix-name}";
   }
   else pkgs.haskell-nix.tool compiler-nix-name "cabal" {
@@ -48,7 +48,7 @@
     # Cabal 3.2.1.0 no longer supports he mix of `cabal-version`,
     # lack of `custom-setup` and `v1-install` used by ghcjs boot.
     cabalProjectLocal = ''
-      constraints: Cabal <3.2.1.0
+      constraints: Cabal <3.2.1.0, Cabal-syntax <0
     '';
     materialized = ../materialized/ghcjs/cabal + "/${compiler-nix-name}";
   }