stack: provide hpack 0.38.1 to match upstream binaries

pkgs/development/haskell-modules/configuration-common.nix

@@ -2228,12 +2228,15 @@ with haskellLib;
 
   # stack-3.7.1 requires Cabal < 3.12
   stack =
+    let
+      stack' = super.stack.overrideScope (self: super: { hpack = self.hpack_0_38_1; });
+    in
     if lib.versionOlder self.ghc.version "9.10" then
-      super.stack
+      stack'
     else
       lib.pipe
         # to reduce rebuilds, don't override Cabal in the entire scope
-        ((super.stack.override { Cabal = self.Cabal_3_10_3_0; }).overrideScope (
+        ((stack'.override { Cabal = self.Cabal_3_10_3_0; }).overrideScope (
           self: super:
           let
             downgradeCabal =

pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml

@@ -89,6 +89,7 @@ extra-packages:
   - hasql-pool < 1.1                    # 2025-01-19: Needed for building postgrest
   - hasql-transaction < 1.1.1           # 2025-01-19: Needed for building postgrest
   - hlint == 3.6.*                      # 2025-04-14: needed for hls with ghc-lib-parser 9.6
+  - hpack == 0.38.1                     # 2025-09-18: to match exact version upstream stack-3.7.1 uses
   - hspec-megaparsec == 2.2.0           # 2023-11-18: Latest version compatible with ghc 9.0
   - language-javascript == 0.7.0.0      # required by purescript
   - lsp < 2.5                           # 2024-07-08: need for koka

pkgs/development/haskell-modules/configuration-nix.nix

@@ -1881,16 +1881,23 @@ builtins.intersectAttrs super {
   extensions = enableSeparateBinOutput super.extensions;
 
   # These test cases access the network
-  hpack = overrideCabal (drv: {
-    testFlags = drv.testFlags or [ ] ++ [
-      "--skip"
-      "/Hpack.Defaults/ensureFile/with 404/does not create any files/"
-      "--skip"
-      "/Hpack.Defaults/ensureFile/downloads file if missing/"
-      "--skip"
-      "/EndToEnd/hpack/defaults/fails if defaults don't exist/"
-    ];
-  }) super.hpack;
+  inherit
+    (lib.mapAttrs (
+      _:
+      overrideCabal (drv: {
+        testFlags = drv.testFlags or [ ] ++ [
+          "--skip"
+          "/Hpack.Defaults/ensureFile/with 404/does not create any files/"
+          "--skip"
+          "/Hpack.Defaults/ensureFile/downloads file if missing/"
+          "--skip"
+          "/EndToEnd/hpack/defaults/fails if defaults don't exist/"
+        ];
+      })
+    ) super)
+    hpack
+    hpack_0_38_1
+    ;
 
   doctest = overrideCabal (drv: {
     testFlags = drv.testFlags or [ ] ++ [