Mono:DllImport无法加载库'(null)'

我试着用 C# ZeroMQ bindings

Unhandled Exception: System.DllNotFoundException: libzmq
  at (wrapper managed-to-native) ZMQ/C:zmq_init (int)
  at ZMQ+Context..ctor (Int32 io_threads) [0x00000] in <filename unknown>:0 
  at local_lat.Main (System.String[] args) [0x00000] in <filename unknown>:0

此功能很简单:

    [DllImport("libzmq", CallingConvention = CallingConvention.Cdecl)]
    public static extern IntPtr zmq_init(int io_threads);

当我使用MONO\u LOG\u LEVEL=debug时,MONO显示它正在寻找libzmq,但不断失败,例如:

Mono: DllImport loading library: './libzmq.dylib'.
Mono: DllImport error loading library '(null)'.

我试过搬家库zmq.dylib到本地文件夹并设置libzmq.dll.config文件文件,都没用。

单核细胞增多症找不到明显的原因吗库zmq.dylib,位于/usr/local/lib中?为什么错误会变成“(null)”?