[v2] IE 11 'Promise' is undefined error

Description

IE 11 throws “Unhandled promise rejection ReferenceError: ‘Promise’ is undefined” error in v2 sites. This can be observed at next.gatsbyjs.org and can replicate it locally on my site. Including promise polyfill fixes the issue, but from looking at documentation babel-polyfill is meant to handle that based on defined browsers list.

Steps to reproduce

• Open next.gatsbyjs.org in IE 11
• Observe “Unhandled promise rejection ReferenceError: ‘Promise’ is undefined” error thrown in console longs

Expected result

No promise related errors.

Actual result

Unhandled promise rejection ReferenceError: 'Promise' is undefined
   "Unhandled promise rejection"
   {
      [functions]: ,
      __proto__: { },
      description: "'Promise' is undefined",
      message: "'Promise' is undefined",
      name: "ReferenceError",
      number: -2146823279,
      stack: "ReferenceError: 'Promise' is undefined
   at t.components.component---src-pages-index-js (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:6:70060)
   at Anonymous function (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:6:32261)
   at O (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:24:11838)
   at S (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:6:31869)
   at E (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:6:32413)
   at A.getResourcesForPathname (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:6:34343)
   at Anonymous function (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:24:17870)
   at a (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:24:10747)
   at Anonymous function (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:24:10894)
   at c (https://next.gatsbyjs.org/app-ba276550eb4051a9bc0a.js:24:8307)"
   }

Environment

This is from my own site directory.

  System:
    OS: macOS High Sierra 10.13.5
    CPU: x64 Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz
    Shell: 5.3 - /bin/zsh
  Binaries:
    Node: 8.11.1 - /usr/local/bin/node
    Yarn: 1.6.0 - /usr/local/bin/yarn
    npm: 6.1.0 - /usr/local/bin/npm
  Browsers:
    Chrome: 67.0.3396.87
    Firefox: 60.0.1
    Safari: 11.1.1
  npmPackages:
    gatsby: ^2.0.0-beta.9 => 2.0.0-beta.9 
    gatsby-plugin-glamor: ^2.0.0-beta.2 => 2.0.0-beta.2 
    gatsby-plugin-manifest: ^2.0.2-beta.2 => 2.0.2-beta.2 
    gatsby-plugin-netlify: ^2.0.0-beta.2 => 2.0.0-beta.2 
    gatsby-plugin-offline: ^2.0.0-beta.2 => 2.0.0-beta.2 
    gatsby-plugin-react-helmet: ^3.0.0-beta.2 => 3.0.0-beta.2 
    gatsby-plugin-sitemap: ^2.0.0-beta.2 => 2.0.0-beta.2 
  npmGlobalPackages:
    gatsby-cli: 2.0.0-beta.1

File contents (if changed)

gatsby-config.js: N/A package.json: N/A gatsby-node.js: N/A gatsby-browser.js: N/A gatsby-ssr.js: N/A

[superbull]

This error still exists during development, with Gatsby develop.

Production is OK, with Gatsby build.

Gatsby version: 2.6.2

[johndaskovsky]

We’re running Gatsby 2.13.83 in production and are seeing this issue on IE11