403 Error on 404 Page

[alecdibble]

I have recently encountered a very odd error while utilizing this buildpack. Here is my static.json (all urls changed to hide proprietary info):

{
  "root": "dist/",
  "error_page": "404.html",
  "clean_urls": true,
  "proxies": {
    "/gift-cards": {
      "origin": "https://www.test.com/test"
    }
  },
  "redirects": {
    "/": {
      "url": "/test"
    }
  },
  "https_only": true
}

Here is my directory structure:

When trying to access a page that 404s on Heroku, I get the follow error in the logs:

app[web.1]: 2017/02/02 02:13:16 [error] 23#0: *6 directory index of "./dist/" is forbidden, client: 10.146.110.248, server: , request: "GET / HTTP/1.1", host: "www.test.com"

[alecdibble]

I solved the issue on my fork: https:/alecdibble/heroku-buildpack-static