How to override llvm

I’m trying override llvm-18.1.8 called by zig. No success at all. Sometimes zig calling two derivations of llvm ( old and new ). Purpose of override is massive rebuild with enabling paralellBuildByDefault. Llvm build stuck ( 10 hours and more ) at test. I want disable doCheck for llvm-18.1.8.
Could someone done something like that?

[nix-shell:~]$ nix-info -m

  • system: "x86_64-linux"
  • host os: Linux 6.12.10-lqx1, NixOS, 25.05 (Warbler), 25.05.20250213.2ff53fe
  • multi-user?: yes
  • sandbox: yes
  • version: nix-env (Nix) 2.24.12
  • nixpkgs: /nix/store/brjzz8wv5k09bq0yrvhc1j4hd8677k21-source

nh os switch( without overlay):
┏━ Dependency Graph:
┃ ┌─ ⏵ llvm-18.1.8 (unpackPhase) :stopwatch: 4s
┃ ┌─ :pause_button: zig-0.13.0
┃ ┌─ :pause_button: zig-hook
┃ │ ┌─ ⏵ llvm-19.1.7 (unpackPhase) :stopwatch: 5s
┃ │ ┌─ :pause_button: clang-19.1.7
┃ │ ┌─ :pause_button: hotdoc-0.15
┃ │ ┌─ :pause_button: gstreamer-1.24.10
┃ │ ┌─ :pause_button: gst-plugins-bad-1.24.10
┃ │ ┌─ :pause_button: gtk4-4.16.12
┃ ├─ :pause_button: libadwaita-1.6.4
┃ ┌─ :pause_button: ghostty-1.1.2
┃ ┌─ :pause_button: system-path
┃ ┌─ :pause_button: set-environment
┃ ┌─ :pause_button: etc-profile
┃ ┌─ :pause_button: etc
:pause_button: nixos-system-nixos-25.05.20250218.73cf49b
┣━━━ Builds
┗━ ∑ ⏵ 2 │ :heavy_check_mark: 0 │ :pause_button: 874 │ :stopwatch: 24s^C

With override applied :
┏━ Dependency Graph:
┃ ┌─ ⏵ llvm-18.1.8 (configurePhase) :stopwatch: 15s
┃ ┌─ :pause_button: zig-0.13.0
┃ ┌─ :pause_button: zig-hook
┃ ┌─ :pause_button: ghostty-1.1.2
┃ │ ┌─ ⏵ coreutils-9.5 (configurePhase) :stopwatch: 14s
┃ │ ┌─ :pause_button: openssl-3.3.2
┃ │ ┌─ :pause_button: curl-8.11.1
┃ │ ┌─ :pause_button: patchutils-0.3.3.tar.xz
┃ │ ┌─ :pause_button: patchutils-0.3.3
┃ │ ┌─ :pause_button: d970c9126c033ebcbb7187bc705eae2e54726b74.patch
┃ │ ├─ ⏵ llvm-18.1.8 (configurePhase) :stopwatch: 16s
┃ │ ┌─ :pause_button: SPIRV-LLVM-Translator-18.1.0
┃ │ ├─ ⏵ llvm-19.1.7 (configurePhase) :stopwatch: 17s
┃ │ ┌─ :pause_button: mesa-24.3.4
┃ │ ┌─ :pause_button: xorg-server-21.1.15
┃ │ ┌─ :pause_button: gdm-47.0
┃ │ ┌─ :pause_button: gnome-shell-47.4
┃ ├─ :pause_button: gnome-browser-connector-42.1
┃ ┌─ :pause_button: system-path
:pause_button: nixos-system-nixos-25.05.20250218.73cf49b
┣━━━ Builds
┗━ ∑ ⏵ 4 │ :heavy_check_mark: 0 │ :pause_button: 883 │ :stopwatch: 33s^C
I’m using :
packageOverrides = pkgs: {
llvm = pkgs.llvmPackages_18.llvm.dev.overrideAttrs (attrs: { doCheck = false; doInstallCheck = false; dontCheck = true; strictDeps = false; });
};