Error after build: Uncaught TypeError n(...) is not a function (prop-types)

[RobertBolender]

Gatsby: 1.9.202

I haven't been able to reliably reproduce the issue, but thought I'd post this just in case someone else has noticed a similar issue.

More than once, I've noticed that when I load my site after a fresh production build, some of the content will load and some will not. My first thought was that my layout/index.js was loading but not the page content, but upon inspecting the DOM I found that the page elements were there but not fully rendered.

The javascript console included this error:

Clicking on the first index.js:27 link showed me what appears to be code from the prop-types package, which led me to think it could be related to this prop-types webpack issue

The error persists through page refreshes until I clear the cache with a hard Ctrl+F5 refresh.

I realize that I haven't provided much to go on in terms of reproducing the bug, but would be happy to learn how I can better debug this.

[RobertBolender]

On subsequent builds, I have seen other errors, but the visible result is the same: I have a header/footer rendered fully, but the inner contents of each page isn't fully rendered.

Once I clear my cache and refresh, everything goes back to normal.

[KyleAMathews]

I'd guess you're caching the JavaScript? https://www.gatsbyjs.org/docs/caching/

[RobertBolender]

@KyleAMathews Ah, it appears you are correct. I remember reading that page and so had not implemented any JS caching myself, but I failed to check whether my server setup had caching in place already (and it does). Thanks for the help.