Gatsby: Build issue when using gatsby-plugin-netlify-cms

[acarl]

I'm receiving the following error on the production but not the develop build when using gatsby-plugin-netlify-cms. I was using this plugin before but on an older version of gatsby. After I upgraded gatsby (among other things) I am getting this error. If I remove gatsby-plugin-netlify-cms I no longer get the error.

Error: app-ffa06f381625a48fea6d.js from UglifyJs
  SyntaxError: Unexpected character '`' [./~/gatsby-plugin-netlify-cms/gatsby-br  owser.js:10,0]

Could this potentially be related to this recent pull request?
https://github.com/gatsbyjs/gatsby/pull/4215

[erquhart]

Reproduced, investigating.

[Flaque]

Also getting this

[martynhoyer]

I mentioned this issue within https://github.com/gatsbyjs/gatsby/issues/4227#issuecomment-368295263

There's a PR open:
https://github.com/gatsbyjs/gatsby/pull/4233

[cpilson]

If you absolutely must get past this error, and aren't using Travis-CI, you can replace ` in the file with '

The file is located at node_modules/gatsby-plugin-netlify-cms/gatsby-browser.js

[erquhart]

Fixed in #4233 (pending release).