From 2a588dad4ee6f53b1a926f003266395f0845a203 Mon Sep 17 00:00:00 2001
From: Andrew Childs <lorne@cons.org.nz>
Date: Fri, 19 Mar 2021 20:40:34 +0900
Subject: [PATCH] llvmPackages_{10,11}.compiler-rt: restrict build to current
 arch

Workaround for build failure after adding mandatory -arch
argument. Nixpkgs targets a single architecture, so this saves a small
amount of wasted build effort.

See https://github.com/NixOS/nixpkgs/pull/114817#issuecomment-802709527
---
 pkgs/development/compilers/llvm/10/compiler-rt.nix | 1 +
 pkgs/development/compilers/llvm/11/compiler-rt.nix | 1 +
 2 files changed, 2 insertions(+)

diff --git a/pkgs/development/compilers/llvm/10/compiler-rt.nix b/pkgs/development/compilers/llvm/10/compiler-rt.nix
index bdc99427c27e..64d57e3e811d 100644
--- a/pkgs/development/compilers/llvm/10/compiler-rt.nix
+++ b/pkgs/development/compilers/llvm/10/compiler-rt.nix
@@ -46,6 +46,7 @@ stdenv.mkDerivation rec {
     # and finds i386;x86_64;x86_64h. We only build for x86_64, so linking fails
     # when it tries to use libc++ and libc++api for i386.
     "-DDARWIN_osx_ARCHS=${stdenv.hostPlatform.darwinArch}"
+    "-DDARWIN_osx_BUILTIN_ARCHS=${stdenv.hostPlatform.darwinArch}"
   ];
 
   outputs = [ "out" "dev" ];
diff --git a/pkgs/development/compilers/llvm/11/compiler-rt.nix b/pkgs/development/compilers/llvm/11/compiler-rt.nix
index fe326b004131..88a412f6cb4f 100644
--- a/pkgs/development/compilers/llvm/11/compiler-rt.nix
+++ b/pkgs/development/compilers/llvm/11/compiler-rt.nix
@@ -27,6 +27,7 @@ stdenv.mkDerivation rec {
   ] ++ lib.optionals (stdenv.isDarwin) [
     "-DDARWIN_macosx_OVERRIDE_SDK_VERSION=ON"
     "-DDARWIN_osx_ARCHS=${stdenv.hostPlatform.darwinArch}"
+    "-DDARWIN_osx_BUILTIN_ARCHS=${stdenv.hostPlatform.darwinArch}"
   ] ++ lib.optionals (useLLVM || bareMetal || isMusl) [
     "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
     "-DCOMPILER_RT_BUILD_XRAY=OFF"