haskellPackages.iserv-proxy: fix on GHC 9.6

pkgs/development/haskell-modules/configuration-ghc-9.6.x.nix

@@ -38,7 +38,6 @@ in
   haskeline = null;
   hpc = null;
   integer-gmp = null;
-  libiserv = null;
   mtl = null;
   parsec = null;
   pretty = null;
@@ -60,6 +59,10 @@ in
   xhtml = null;
   Win32 = null;
 
+  libiserv = doJailbreak (markUnbroken (doDistribute super.libiserv)); # ghci ==9.6.6
+
+  iserv-proxy = addBuildDepend self.libiserv super.iserv-proxy;
+
   # Becomes a core package in GHC >= 9.8
   semaphore-compat = doDistribute self.semaphore-compat_1_0_0;
 

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

@@ -2239,8 +2239,9 @@ builtins.intersectAttrs super {
           enableExternalInterpreter = false;
         };
       in
-      lib.mapAttrs (_: noExternalInterpreter) { inherit (super) iserv-proxy network; }
+      lib.mapAttrs (_: noExternalInterpreter) { inherit (super) libiserv iserv-proxy network; }
     )
+    libiserv
     iserv-proxy
     network
     ;

pkgs/development/haskell-modules/generic-builder.nix

@@ -26,8 +26,9 @@ let
     needsExternalInterpreterSetup = !stdenv.hostPlatform.isGhcjs; # JS backend already handles this
 
     canProxyTH =
-      # iserv-proxy currently does not build on GHC 9.6
-      lib.versionAtLeast ghc.version "9.8" && stdenv.hostPlatform.emulatorAvailable buildPackages;
+      # Using iserv-proxy with 9.4 yields
+      #   no location info>: error: Dynamic loading not supported
+      lib.versionAtLeast ghc.version "9.6" && stdenv.hostPlatform.emulatorAvailable buildPackages;
 
     iservWrapper =
       let

pkgs/development/tools/haskell/iserv-proxy/default.nix

@@ -15,14 +15,14 @@
 }:
 mkDerivation {
   pname = "iserv-proxy";
-  version = "9.3-unstable-2025-10-30";
+  version = "9.3-unstable-2026-02-04";
 
   # https://github.com/stable-haskell/iserv-proxy/pull/1
   src = fetchFromGitHub {
     owner = "stable-haskell";
     repo = "iserv-proxy";
-    rev = "bbee090fc67bb5cc6ad4508fa5def560b7672591";
-    hash = "sha256-2aCGboNCF602huvmbyTcfhe6s+D4/n/NlOefd0c0SC0=";
+    rev = "91ef7ffdeedfb141a4d69dcf9e550abe3e1160c6";
+    hash = "sha256-x6QYupvHZM7rRpVO4AIC5gUWFprFQ59A95FPC7/Owjg";
   };
 
   isLibrary = true;