build error

[bwanaaa]

% ./mkapp
internal/modules/cjs/loader.js:888
throw err;
^

Error: Cannot find module 'nw-builder'
Require stack:

• /private/tmp/appbuild.js
  at Function.Module._resolveFilename (internal/modules/cjs/loader.js:885:15)
  at Function.Module._load (internal/modules/cjs/loader.js:730:27)
  at Module.require (internal/modules/cjs/loader.js:957:19)
  at require (internal/modules/cjs/helpers.js:88:18)
  at Object. (/private/tmp/appbuild.js:1:17)
  at Module._compile (internal/modules/cjs/loader.js:1068:30)
  at Object.Module._extensions..js (internal/modules/cjs/loader.js:1097:10)
  at Module.load (internal/modules/cjs/loader.js:933:32)
  at Function.Module._load (internal/modules/cjs/loader.js:774:14)
  at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ '/private/tmp/appbuild.js' ]
  }
  ERROR: Failed to package MeshCommander.app

what/where is appbuild.js?