From 79a87d6750773315ce8ec9b0dfa52717a13e3aff Mon Sep 17 00:00:00 2001
From: sternenseemann <sternenseemann@systemli.org>
Date: Tue, 3 Mar 2026 18:50:52 +0100
Subject: [PATCH] haskell.packages.ghc902Binary: fix evaluation of package set

These attributes need to be present, so that callPackage doesn't fail
with an unrecoverable error on some members of the package set. This
is not necessary for any package Hydra builds, but helps for listing/
inspecting the package set.
---
 .../haskell-modules/configuration-ghc-9.0.x.nix | 17 +++++++++++++++++
 .../configuration-hackage2nix/main.yaml         |  1 +
 .../haskell-modules/hackage-packages.nix        | 14 ++++++++++++++
 3 files changed, 32 insertions(+)

diff --git a/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix b/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix
index 1454ea63b514..1fffe94c2a2c 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-9.0.x.nix
@@ -37,4 +37,21 @@ self: super: {
   unix = null;
   xhtml = null;
   Win32 = null;
+
+  # core pkgs on later GHCs that we can reasonably provide a stub
+  # or Hackage released version for (though they may not build).
+  Cabal-syntax = self.Cabal-syntax_3_6_0_0;
+  semaphore-compat = self.semaphore-compat_2_0_0;
+  os-string = self.os-string_2_0_10;
+  file-io = self.file-io_0_2_0;
+  # Would need 2.25.*, but let's not bother
+  haddock-api = self.haddock-api_2_29_1;
+  haddock-library = self.haddock-library_1_11_0;
+
+  # core pkgs on later GHCs we can't provide at all
+  system-cxx-std-lib = null;
+  ghc-experimental = null;
+  ghc-internal = null;
+  ghc-platform = null;
+  ghc-toolchain = null;
 }
diff --git a/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml b/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
index cb007baa533e..4fc015f6b294 100644
--- a/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
+++ b/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
@@ -78,6 +78,7 @@ extra-packages:
   - Cabal == 3.14.*
   - Cabal == 3.16.*                     # version required for cabal-install and other packages
   - cabal-add == 0.1                    # 2025-09-09: Only needed for hls 2.11 can be removed once we are past it.
+  - Cabal-syntax == 3.6.*               # required for the GHC 9.0.2 package set
   - Cabal-syntax == 3.10.*
   - Cabal-syntax == 3.12.*
   - Cabal-syntax == 3.14.*
diff --git a/pkgs/development/haskell-modules/hackage-packages.nix b/pkgs/development/haskell-modules/hackage-packages.nix
index 97edc71c12d7..d3be4304a3da 100644
--- a/pkgs/development/haskell-modules/hackage-packages.nix
+++ b/pkgs/development/haskell-modules/hackage-packages.nix
@@ -6122,6 +6122,20 @@ self: {
     }
   ) { };
 
+  Cabal-syntax_3_6_0_0 = callPackage (
+    { mkDerivation, Cabal }:
+    mkDerivation {
+      pname = "Cabal-syntax";
+      version = "3.6.0.0";
+      sha256 = "0lcj4g55sj5iv727g7k57pscgyj0fx3smwapm1gmd5qkc3yfa9fa";
+      libraryHaskellDepends = [ Cabal ];
+      doHaddock = false;
+      description = "A library for working with .cabal files";
+      license = lib.licenses.bsd3;
+      hydraPlatforms = lib.platforms.none;
+    }
+  ) { };
+
   Cabal-syntax_3_10_3_0 = callPackage (
     {
       mkDerivation,