{ name, lib, config, ... }:

{
  system.includeBuildDependencies = true;
  system.switch.enable = true;

  documentation.enable = false;

  virtualisation = {
    additionalPaths = [ config.system.build.toplevel ];
    writableStore = true;
    mountHostNixStore = true;
    installBootLoader = true;

    # Moderately improves performance of `nixos-rebuild` inside the VM on my machine,
    # (205.48 seconds to 186.42 seconds), but we have to allocate much more space.
    writableStoreUseTmpfs = false;
    # 20 GiB ought to be enough.
    diskSize = lib.mkIf (!config.virtualisation.writableStoreUseTmpfs) (20 * 1024);

    # With how much memory Nix eval uses, this is essentially required.
    memorySize = 8192;
    cores = 8;

  };

  boot.loader.grub = {
    enable = true;
    device = "/dev/vda";
    forceInstall = true;
  };

  # Just making something in this strict in `name`,
  # which is only present as an argument for nodes and I don't want to
  # confuse that with the test modules.
  warnings = builtins.seq name [ ];
}