From f7445ae7398387df587c96a4406c753bed60283c Mon Sep 17 00:00:00 2001
From: lassulus <lassulus@lassul.us>
Date: Sun, 25 Dec 2022 21:15:32 +0100
Subject: [PATCH] module: define only if devices are given

---
 module.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/module.nix b/module.nix
index 40b7490..b216132 100644
--- a/module.nix
+++ b/module.nix
@@ -5,7 +5,8 @@ let
 in {
   options.disko = {
     devices = lib.mkOption {
-      type = types.devices;
+      type = lib.types.nullOr types.devices;
+      default = null;
     };
     enableConfig = lib.mkOption {
       description = ''
@@ -17,7 +18,7 @@ in {
       default = true;
     };
   };
-  config = {
+  config = lib.mkIf (cfg.devices != null) {
     system.build.formatScript = pkgs.writers.writeDash "disko-create" ''
       export PATH=${lib.makeBinPath (types.diskoLib.packages cfg.devices pkgs)}:$PATH
       ${types.diskoLib.create cfg.devices}