Workaround https://github.com/minetest/minetest/issues/7020

mods/nc_api/init.lua

@@ -11,6 +11,8 @@ rawset(_G, "nodecore", nodecore)
 
 local path = minetest.get_modpath(modname)
 
+dofile(path .. "/issue7020.lua")
+
 dofile(path .. "/util_misc.lua")
 dofile(path .. "/util_scan_flood.lua")
 dofile(path .. "/util_logtrace.lua")

mods/nc_api/issue7020.lua

@@ -0,0 +1,22 @@
+-- LUALOCALS < ---------------------------------------------------------
+local minetest, pairs, setmetatable, type
+    = minetest, pairs, setmetatable, type
+-- LUALOCALS > ---------------------------------------------------------
+
+local bifn = minetest.registered_entities["__builtin:falling_node"]
+local falling = {
+	set_node = function(self, node, meta, ...)
+		meta = meta or {}
+		if type(meta) ~= "table" then meta = meta:to_table() end
+		for k1, v1 in pairs(meta.inventory or {}) do
+			for k2, v2 in pairs(v1) do
+				if type(v2) == "userdata" then
+					v1[k2] = v2:to_string()
+				end
+			end
+		end
+		return bifn.set_node(self, node, meta, ...)
+	end
+}
+setmetatable(falling, bifn)
+minetest.register_entity(":__builtin:falling_node", falling)

mods/nc_fire/init.lua

@@ -9,4 +9,3 @@ local path = minetest.get_modpath(modname)
 dofile(path .. "/api.lua")
 dofile(path .. "/node.lua")
 dofile(path .. "/abm.lua")
-

mods/nc_lode/init.lua

@@ -8,4 +8,3 @@ local path = minetest.get_modpath(modname)
 
 dofile(path .. "/ore.lua")
 dofile(path .. "/metallurgy.lua")
-

mods/nc_tree/node.lua

@@ -62,4 +62,3 @@ nodecore.register_leaf_drops(function(pos, node, list)
 	end)
 
 local function fixed(t) return {type = "fixed", fixed = t} end
-