llvmPackages.libllvm: disable tests when built in the Darwin bootstrap

When using the LLVM bootstrap to build LLVM and its libraries,
overriding just LLVM to disable tests during the first build doesn’t
seem to work. This stage name should remain stable, so check for it and
disable tests when building in it.

pkgs/development/compilers/llvm/common/llvm/default.nix

@@ -17,6 +17,7 @@
   # TODO: Can this memory corruption bug still occur?
   # <https://github.com/llvm/llvm-project/issues/61350>
 , enableGoldPlugin ? libbfd.hasPluginAPI
+, ld64
 , libbfd
 , libpfm
 , libxml2
@@ -46,6 +47,11 @@
 let
   inherit (lib) optional optionals optionalString;
 
+  # Is there a better way to do this? Darwin wants to disable tests in the first
+  # LLVM rebuild, but overriding doesn’t work when building libc++, libc++abi,
+  # and libunwind. It also wants to disable LTO in the first rebuild.
+  isDarwinBootstrap = lib.getName stdenv == "bootstrap-stage-xclang-stdenv-darwin";
+
   # Used when creating a version-suffixed symlink of libLLVM.dylib
   shortVersion = lib.concatStringsSep "." (lib.take 1 (lib.splitString "." release_version));
 
@@ -66,7 +72,7 @@ let
   #
   # So, we "manually" assemble one python derivation for the package to depend
   # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
+  python = if doCheck && !isDarwinBootstrap then
     # Note that we _explicitly_ ask for a python interpreter for our host
     # platform here; the splicing that would ordinarily take care of this for
     # us does not seem to work once we use `withPackages`.
@@ -91,14 +97,14 @@ let
   patches' = patches ++ lib.optionals enablePolly pollyPatches;
 in
 
-stdenv.mkDerivation (rec {
+stdenv.mkDerivation (finalAttrs: {
   inherit pname version;
 
   src = src';
   patches = patches';
 
   sourceRoot = if lib.versionOlder release_version "13" then null
-    else "${src.name}/${pname}";
+    else "${finalAttrs.src.name}/${pname}";
 
   outputs = [ "out" "lib" "dev" "python" ];
 
@@ -342,13 +348,13 @@ stdenv.mkDerivation (rec {
     ];
   in flagsForLlvmConfig ++ [
     "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
+    "-DLLVM_BUILD_TESTS=${if finalAttrs.finalPackage.doCheck then "ON" else "OFF"}"
     "-DLLVM_ENABLE_FFI=ON"
     "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
     "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
     "-DLLVM_ENABLE_DUMP=ON"
     (lib.cmakeBool "LLVM_ENABLE_TERMINFO" enableTerminfo)
-  ] ++ optionals (!doCheck) [
+  ] ++ optionals (!finalAttrs.finalPackage.doCheck) [
     "-DLLVM_INCLUDE_TESTS=OFF"
   ] ++ optionals stdenv.hostPlatform.isStatic [
     # Disables building of shared libs, -fPIC is still injected by cc-wrapper
@@ -428,7 +434,7 @@ stdenv.mkDerivation (rec {
     cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
   '');
 
-  inherit doCheck;
+  doCheck = !isDarwinBootstrap && doCheck;
 
   checkTarget = "check-all";