Revert the toolchain changes for v15

default.nix

@@ -1,5 +1,6 @@
 {
-    nixPkgsVersion ? "3e52e76b70d5508f3cec70b882a29199f4d1ee85"
+    nixPkgsVersion ? "3e52e76b70d5508f3cec70b882a29199f4d1ee85",
+    currentSystem
 }:
 let
 
@@ -12,21 +13,17 @@ let
         rev = nixPkgsVersion;
     }) args;
 
-    nixpkgs = getNixPkgs {};
-    system = import ./system.nix { pkgs = nixpkgs; };
+    nixpkgs = getNixPkgs { system = currentSystem; };
+    system = import ./system.nix {
+        pkgs = nixpkgs;
+        inherit currentSystem;
+    };
     staticMuslPkgs = getNixPkgs system;
-    llvm = staticMuslPkgs.llvmPackages_16.override { stdenv = staticMuslPkgs.llvmPackages_16.libcxxClang; };
-    SereneOverlay = final: prev:
-        {
-              sereneToolchain = llvm.libcxxClang;
-        };
+    llvm = staticMuslPkgs.llvmPackages_16.override { stdenv = staticMuslPkgs.llvmPackages_16.libcxxStdenv; };
 
     createPkgSet = _: # It has to be the nixpkgs instance
-        getNixPkgs (system // { overlays = [ SereneOverlay ]; });
-    #pkgs = getNixPkgs nixVersion (system // { overlays = [ libcxxClangOverlay ]; });
-in {
-    inherit SereneOverlay createPkgSet;
-    # setupToolchain = nixpkgs:
+        getNixPkgs (system // { config.replaceStdenv = _: llvm.libcxxStdenv; });
 
-    #pkgs.stdenv.override { stdenv = llvm.libcxxClang; };
+in {
+    inherit createPkgSet;
 }

system.nix

@@ -1,11 +1,11 @@
-{ pkgs }:
+{ pkgs, currentSystem }:
 let
-    parsedSystem = builtins.split "-" builtins.currentSystem;
+    parsedSystem = builtins.split "-" currentSystem;
     arch = builtins.head (parsedSystem);
     os = builtins.elemAt (parsedSystem) 2;
 
     system = pkgs.lib.systems.elaborate {
-        system = builtins.currentSystem;
+        system = currentSystem;
         config = "${arch}-unknown-linux-musl";
         isStatic = true;
         useLLVM = true;