From 8cb7f599f9e488f7e0ed320ab8d437b488ba079a Mon Sep 17 00:00:00 2001
From: Matthew Leach <dev@mattleach.net>
Date: Fri, 8 Apr 2022 16:26:54 +0100
Subject: [PATCH] haskell.compiler.ghc902: fix seperate bin outputs on
 aarch64-darwin

---
 pkgs/development/compilers/ghc/9.0.2.nix | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/pkgs/development/compilers/ghc/9.0.2.nix b/pkgs/development/compilers/ghc/9.0.2.nix
index 0968b8539922..1f94dd3bbde2 100644
--- a/pkgs/development/compilers/ghc/9.0.2.nix
+++ b/pkgs/development/compilers/ghc/9.0.2.nix
@@ -192,6 +192,15 @@ stdenv.mkDerivation (rec {
       url = "https://gitlab.haskell.org/ghc/ghc/-/commit/c6132c782d974a7701e7f6447bdcd2bf6db4299a.patch?merge_request_iid=7423";
       sha256 = "sha256-b4feGZIaKDj/UKjWTNY6/jH4s2iate0wAgMxG3rAbZI=";
     })
+  ] ++ lib.optionals (stdenv.isDarwin && stdenv.isAarch64) [
+
+    # Prevent the paths module from emitting symbols that we don't use
+    # when building with separate outputs.
+    #
+    # These cause problems as they're not eliminated by GHC's dead code
+    # elimination on aarch64-darwin. (see
+    # https://github.com/NixOS/nixpkgs/issues/140774 for details).
+    ./cabal-paths.patch
   ];
 
   postPatch = "patchShebangs .";