Thumbnail is absent in MarkdownRemark

[arnondora]

I quite a bit weird when I open the post page from the link of others page, thumbnail address has null value but when I open the post page via a direct link or just refresh the page, the thumbnail is shown. This problem happens only in build only, the develop one works smoothly.

Environment

Gatsby version: 1.9.199
Node.js version: 6.11.4
Operating System: macOS 10.13.3

Step to reproduce

• Open new gatsby project along with installing markdownremark plugin
• Create template as a post page with thumbnail
• Create Post Content in markdown style
• Build the project by run gatsby build
• Serve project by run gatsby serve

You may checkout this repository in develop branch to see the problem and the result is in this site

[arnondora]

When I want to use the thumbnail, I have to check the existent of thumbnail since there's a post that has no thumbnail. I use get() from lodash. The way I import is

import get from 'lodash/get'

I think importing in this way might cause the problem, since I change to import get like this

import { get } from 'lodash'

The problem is gone...