This will cause the assert on line 184 of functions.d to fire.

luad_non_empty_stack.d

version(Windows) {
	pragma(lib, "lua51.lib");
} else
	pragma(lib, "liblua.a");


import std.stdio;

import luad.all;

alias string delegate(string) MyFun;

void main() {
	auto lua = new LuaState();
	lua.openLibs();
	MyFun[string] funs;

	void makeCall(string name, string str) {
		funs[name](str);
	}

	void addFun(string name, MyFun fun) {
		funs[name] = fun;
	}

	lua["makeCall"] = &makeCall;
	lua["addFun"] = &addFun;

	lua.doString(q{

function echo(str)
	return str
end

addFun("echo", echo)

makeCall("echo", "hello")
	  
	  });

}