Cryptic Error Message about "Watchman crawl failed"

[epitaphmike]

It seems I installed watchman via brew back in April 2005 when I was experimenting with React-Native. Since then I have not used watchman and completely forgot it was even installed.

That being said, this morning I was running Jest and I received this error.

jest-haste-map: Watchman crawl failed. Retrying once with node crawler. 
Usually this happens when watchman isn't running. Create an empty `.watchmanconfig` file in your project's root folder or initialize a git or hg repository in your project.
Error: Watchman error: unknown command watch-project. Make sure watchman is running for this project. See https://facebook.github.io/watchman/docs/troubleshooting.html.

I have the same repo on another machine without watchman installed and obviously did not receive the error.

It took some digging to figure out what the error was for, if it was Jest related or that I even had watchman installed.

I think it may be helpful in the error message to give a little more context. I am not sure if this is something that should be handled by the Jest team or Watchman team.

I just thought I would offer my two cents.

Thanks.

[wez]

Most of that error text is produced by jest-haste-map, not from watchman; the only part from watchman is the Watchman error: unknown command watch-project text.

The problem here is that jest is using a feature that is only available in a more recent version of watchman than you had installed without checking whether it is supported properly.

I've opened jestjs/jest#2735 for the jest folks with advice on how to improve this.

To resolve the root cause of your issue, you just need to install the current version of watchman as is suggested in the troubleshooting guide URL that is printed out in that error message.

[epitaphmike]

Thanks @wez. I appreciate you opening the other ticket. Hopefully issues like these will bring some of the development between facebook project teams together. Thanks again