{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    nixpkgs-gcc15.url = "github:NixOS/nixpkgs/?ref=pull/401948/head";
    nixpkgs-cmake.url = "github:NixOS/nixpkgs/?ref=pull/394444/head";
  };
  outputs = {
    nixpkgs-cmake,
    nixpkgs-gcc15,
    nixpkgs,
    flake-utils,
    ...
  }:
    flake-utils.lib.eachDefaultSystem (
      system: let
        inherit
          (import nixpkgs-cmake {
            inherit system;
            config = {
              cudaSupport = true;
            };
          })
          cmake
          ;
        inherit
          (import nixpkgs-gcc15 {
            inherit system;
            config = {
              cudaSupport = true;
            };
          })
          gcc15
          gcc15Stdenv
          ;
        pkgs = import nixpkgs {
          inherit system;
          config = {
            cudaSupport = true;
          };
        };
      in {
        devShells.default =
          pkgs.mkShell.override
          {
            stdenv = pkgs.llvmPackages_20.libcxxStdenv;
            # stdenv = gcc15Stdenv;
          }
          {
            packages = with pkgs; [
              llvmPackages_20.clang-tools
              gnumake
              llvmPackages_20.clang
              bear
              # cmake
              # gcc15
            ];
          };
      }
    );
}