Cannot find module 'promise' when uploading to heroku

Question

Everything works fine normally on my local server but when I upload to Heroku, I get the following error. Wondering if anyone knows how to fix? I am running an angular front end with a Flask back end. Feel free to let me know what info is useful if you need more.

Error: Cannot find module 'promise'
2015-01-29T02:13:31.947779+00:00 app[web.1]:     at Function.Module._load (module.js:312:12)
2015-01-29T02:13:31.947768+00:00 app[web.1]:     at Function.Module._load (module.js:280:25)
2015-01-29T02:13:31.947781+00:00 app[web.1]:     at Module.require (module.js:362:17)
2015-01-29T02:13:31.947770+00:00 app[web.1]:     at Module.require (module.js:362:17)
2015-01-29T02:13:32.057385+00:00 app[web.1]: 9Z9Z12
2015-01-29T02:13:31.945462+00:00 app[web.1]:           ^
2015-01-29T02:13:31.947766+00:00 app[web.1]:     at Function.Module._resolveFilename (module.js:338:15)
2015-01-29T02:13:31.942359+00:00 app[web.1]: module.js:340

Answer 1

It turns out bower for angular sets up files in a place that is not expected by Heroku and therefore you have to move the Bower stuff to a different area (namely in this case for Flask from the main folder to the static folder.

Hope this helps some other people.