move "dye" to optional depends and disable recipes if default or dye are not available

crafts.lua

@@ -1,14 +1,24 @@
 -- CRAFTING RECIPES FOR SCIFI NODES
 
--- 6 basic plastic from 9 homedecor plastic sheet
-minetest.register_craft({
-	output = "scifi_nodes:white2 6",
-	recipe = {
-		{"homedecor:plastic_sheeting", "homedecor:plastic_sheeting", "homedecor:plastic_sheeting"},
-		{"homedecor:plastic_sheeting", "homedecor:plastic_sheeting", "homedecor:plastic_sheeting"},
-		{"homedecor:plastic_sheeting", "homedecor:plastic_sheeting", "homedecor:plastic_sheeting"}
-	}
-})
+if minetest.get_modpath("basic_materials") then
+    -- 6 basic plastic from 9 homedecor plastic sheet
+    minetest.register_craft({
+        output = "scifi_nodes:white2 6",
+        recipe = {
+            {"homedecor:plastic_sheeting", "homedecor:plastic_sheeting", "homedecor:plastic_sheeting"},
+            {"homedecor:plastic_sheeting", "homedecor:plastic_sheeting", "homedecor:plastic_sheeting"},
+            {"homedecor:plastic_sheeting", "homedecor:plastic_sheeting", "homedecor:plastic_sheeting"}
+        }
+    })
+end
+
+if not minetest.get_modpath("default") or not minetest.get_modpath("dye") then
+    -- the default and dye mod are required for most of the recipes
+    -- if either of them is missing (because we are not in the default game)
+    -- then just skip the recipes entirely
+    -- TODO: potentially switch recipes depending on current game
+    return
+end
 
 minetest.register_craft({
 	output = "scifi_nodes:super_white",

mod.conf

@@ -1,4 +1,15 @@
 name = scifi_nodes
 description = Minetest mod that adds scifi themed blocks, doors, materials, plants and other assets.
-depends = default,dye
-optional_depends = xpanes,mesecons,moreblocks,mesecons_microcontroller,mesecons_button,mesecons_torch,mesecons_receiver,basic_materials,unifieddyes
+depends = default
+optional_depends = """
+xpanes,
+mesecons,
+moreblocks,
+mesecons_microcontroller,
+mesecons_button,
+mesecons_torch,
+mesecons_receiver,
+basic_materials,
+dye
+unifieddyes
+"""