rec {
  # user information
  username = "ryan";
  userfullname = "Ryan Yin";
  useremail = "xiaoyin_c@qq.com";

  allSystemAttrs = {
    # linux systems
    x64_system = "x86_64-linux";
    riscv64_system = "riscv64-linux";
    aarch64_system = "aarch64-linux";
    #darwin systems
    x64_darwin = "x86_64-darwin";
    aarch64_darwin = "aarch64-darwin";
  };
  allSystems = builtins.attrValues allSystemAttrs;
}