only register packed ice when ethereal is not detected

depends.txt

@@ -6,6 +6,7 @@ homedecor
 doors
 stairs
 xpanes
+ethereal?
 3d_armor?
 fire?
 oresplus?

src/nodes.lua

@@ -413,11 +413,18 @@ register_hard_node("desertstone_tile", "Desert Stone Tile")
 register_hard_node("hard_clay", "Hardened Clay")
 register_hard_node("moonbrick", "Moon Brick")
 register_hard_node("stone_tile", "Stone Tile")
-register_hard_node("stone_rune", "Runestone")
-register_hard_node("packed_ice", "Packed Ice", {
+register_hard_node("stone_rune", "Runestone", {
 	groups = {cracky=1, puts_out_fire=1},
 	sounds = default.node_sound_glass_defaults()
 })
+if not minetest.get_modpath("ethereal") then
+    register_hard_node("packed_ice", "Packed Ice", {
+        groups = {cracky=1, puts_out_fire=1},
+        sounds = default.node_sound_glass_defaults()
+    })
+    elseif minetest.get_modpath("ethereal") then
+        minetest.register_alias("xdecor:packed_ice", "ethereal:icebrick")
+end
 register_hard_node("wood_tile", "Wooden Tile", {
 	groups = {choppy=1, wood=1, flammable=2},
 	sounds = default.node_sound_wood_defaults()