private fun gen_makefile(model: Model, mainmodule: MModule): nullable String do
		var filter = new ModelFilter(accept_example = false, accept_test = false)

		var pkg_path = package_path.as(not null)
		var makefile_path = makefile_path.as(not null)

		var bins = new Array[String]
		var cmd_bin = new CmdMains(model, filter, mentity = self)
		var res_bin = cmd_bin.init_command
		if res_bin isa CmdSuccess then
			for mmodule in cmd_bin.results.as(not null) do
				if not mmodule isa MModule then continue
				var mmodule_makefile = mmodule.makefile_path
				if mmodule_makefile != null and mmodule_makefile != makefile_path then continue

				var file = mmodule.location.file
				if file == null then continue
				# Remove package path prefix
				var bin_path = file.filename
				if pkg_path.has_suffix("/") then
					bin_path = bin_path.replace(pkg_path, "")
				else
					bin_path = bin_path.replace("{pkg_path}/", "")
				end
				bins.add bin_path
			end
		end

		if  bins.is_empty then return null

		var make = new NitMakefile(bins)
		make.render.write_to_file(makefile_path)
		return makefile_path
	end