Gatsby build failure: window not defined

[mrjoedang]

Running gatsby build gives the following error:

error Building static HTML failed
  15 |  * True if the custom elements polyfill is in use.
  16 |  */
> 17 | export const isCEPolyfill = window.customElements !== undefined &&
     |        ^
  18 |     window.customElements.polyfillWrapFlushCallback !==
  19 |         undefined;
  20 | /**


  WebpackError: ReferenceError: window is not defined

A temporary solution is to configure gatsby-node.js (as per https://www.gatsbyjs.org/docs/debugging-html-builds/#fixing-third-party-modules) as so:

exports.onCreateWebpackConfig = ({ stage, loaders, actions }) => {
  if (stage === "build-html") {
    actions.setWebpackConfig({
      module: {
        rules: [
          {
            test: /wired/,
            use: loaders.null(),
          },
        ],
      },
    })
  }
}

Refer to gatsbyjs/gatsby#309 for a more permanent solution.

[pshihn]

I have little experience with Gatsby/react in general. But I suspect this has something to do with the webpack tooling setup as you suggested.
WIll look more into this eventually

[pshihn]

This is probably tied to SSR : #16