From b6a3b8846e7a93cbcdf3acff099dd292d710d786 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sun, 28 Dec 2025 15:31:09 +0100
Subject: [PATCH] haskell.lib.buildFromSdist: add test, fix double-patch

Same issue as buildFromCabalSdist: sdistTarball applies patches via
overrideDerivation, but the patches attribute remained, causing
patchPhase to apply them again.
---
 pkgs/development/haskell-modules/lib/compose.nix |  3 ++-
 pkgs/test/haskell/cabalSdist/default.nix         | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/haskell-modules/lib/compose.nix b/pkgs/development/haskell-modules/lib/compose.nix
index 055e6c40c784..372a9417906a 100644
--- a/pkgs/development/haskell-modules/lib/compose.nix
+++ b/pkgs/development/haskell-modules/lib/compose.nix
@@ -482,10 +482,11 @@ rec {
     overrideCabal (drv: {
       src = "${sdistTarball pkg}/${pkg.pname}-${pkg.version}.tar.gz";
 
-      # Revising and jailbreaking the cabal file has been handled in sdistTarball
+      # Revising, jailbreaking and patches have been handled in sdistTarball
       revision = null;
       editedCabalFile = null;
       jailbreak = false;
+      patches = [ ];
     }) pkg;
 
   /*
diff --git a/pkgs/test/haskell/cabalSdist/default.nix b/pkgs/test/haskell/cabalSdist/default.nix
index 1da18146b9d6..05d22e485e12 100644
--- a/pkgs/test/haskell/cabalSdist/default.nix
+++ b/pkgs/test/haskell/cabalSdist/default.nix
@@ -57,4 +57,17 @@ lib.recurseIntoAttrs rec {
         ${lib.getExe localPatchedFromCabalSdist} | grep "Patched" >/dev/null
         touch $out
       '';
+
+  # Test that buildFromSdist (non-cabal-install variant) also respects patches.
+  localPatchedFromSdist = haskell.lib.buildFromSdist localPatched;
+
+  patchRespectedSdist =
+    runCommand "patchRespectedSdist"
+      {
+        nativeBuildInputs = [ localPatchedFromSdist ];
+      }
+      ''
+        ${lib.getExe localPatchedFromSdist} | grep "Patched" >/dev/null
+        touch $out
+      '';
 }