packages/linux-lava: fix clang build issues after nixpkgs changes

overlays/default.nix

@@ -2,6 +2,7 @@ builtins.map (path: import path) [
   ./android-studio.nix
   ./ccache.nix
   ./eww.nix
+  ./linux-lava.nix
   ./material-icons.nix
   ./rofi.nix
   ./steam.nix

overlays/linux-lava.nix

@@ -0,0 +1,23 @@
+self: super: let
+  llvmPackages = super.llvmPackages_19;
+  clangVersion = super.lib.versions.major llvmPackages.libclang.version;
+  cc = llvmPackages.stdenv.cc.override {
+    # :sob: see https://github.com/NixOS/nixpkgs/issues/142901
+    bintools = llvmPackages.bintools;
+    extraBuildCommands = ''
+      substituteInPlace "$out/nix-support/cc-cflags" --replace " -nostdlibinc" ""
+      substituteInPlace "$out/nix-support/add-local-cc-cflags-before.sh" --replace 'echo "Warning: supplying the --target argument to a nix-wrapped compiler may not work correctly - cc-wrapper is currently not designed with multi-target compilers in mind. You may want to use an un-wrapped compiler instead." >&2' ""
+      echo " -resource-dir=${llvmPackages.libclang.lib}/lib/clang/${clangVersion}" >> $out/nix-support/cc-cflags
+    '';
+  };
+  stdenv = super.ccacheStdenv.override {
+    stdenv = super.overrideCC llvmPackages.stdenv cc;
+  };
+in {
+  linuxLavaEnv = {
+    inherit llvmPackages clangVersion cc stdenv;
+  };
+  rust-bindgen-unwrapped = super.rust-bindgen-unwrapped.override {
+    clang = cc;
+  };
+}

packages/linux-lava/default.nix

@@ -1,27 +1,16 @@
 { buildLinux
 , callPackage
-, ccacheStdenv
 , inputs
-, kernelPatches
 , lib
-, llvmPackages_16
-, overrideCC
+, linuxLavaEnv
 , ...
 } @ args:
 
 let
   sources = callPackage ./sources.nix { inherit inputs; };
-  llvmPackages = llvmPackages_16;
   kernel = buildLinux (args // {
     inherit (sources) src kernelPatches;
-    stdenv = ccacheStdenv.override {
-      # :sob: see https://github.com/NixOS/nixpkgs/issues/142901
-      stdenv = overrideCC llvmPackages.stdenv (llvmPackages.stdenv.cc.override {
-        bintools = llvmPackages.bintools.override {
-          sharedLibraryLoader = null;
-        };
-      });
-    };
+    inherit (linuxLavaEnv) stdenv;
     version = "${sources.version}-tkg-Lava";
     isZen = true;
     extraMakeFlags = [ "LLVM=1" "LLVM_IAS=1" ];