我写了一个模块，不久前发布到npm (https://npmjs.org/package/wisp)

所以它可以从命令行安装:

I -g wisp

然而，当我从命令行运行它时，我一直得到一个错误，乐观主义者没有安装:

$ wisp 
Error: Cannot find module 'optimist'
    at Function.Module._resolveFilename (module.js:338:15)
    at Function.Module._load (module.js:280:25)
    at Module.require (module.js:362:17)
    at require (module.js:378:17)
    at Object.<anonymous> (/usr/local/lib/node_modules/wisp/wisp:12:10)
    at Object.<anonymous> (/usr/local/lib/node_modules/wisp/wisp:96:4)
    at Module._compile (module.js:449:26)
    at Object.exports.run (/usr/local/lib/node_modules/coffee-script/lib/coffee-script/coffee-script.js:68:25)
    at compileScript (/usr/local/lib/node_modules/coffee-script/lib/coffee-script/command.js:135:29)
    at fs.stat.notSources.(anonymous function) (/usr/local/lib/node_modules/coffee-script/lib/coffee-script/command.js:110:18)

但是，我已经在包中指定了。Json作为依赖项:

{
  "name": "wisp",
  "author": "Brendan Scarvell <bscarvell@gmail.com>",
  "version": "0.1.0",
  "description": "Global nodejs file server",
  "dependencies": {
    "optimist": "~0.3.4"
  },
  "repository": "git://github.com/tehlulz/wisp",
  "bin": {
    "wisp" : "./wisp"
  }
}

有人知道怎么才能让它运行起来吗?我知道这与bin部分添加可执行文件到bin和该目录中的node_modules为空有关。不知道怎么解决。