vscode-jest: macOS `fsevents unavailable (this watcher can only be used on Darwin)`

brew install watchman fixed the problem for me.

https://github.com/cm-pliser-tdd-by-example/tdd-by-example-js/issues/10#issuecomment-361039205

brew install watchman worked for me too, thanks!

But why? Anyone can explain why we have to run brew install watchman?

You guys should look for the reasons, not just brew install watchman.

There is no documentation says we need install watchman. So why?

I had watchman already installed. I did a full brew reinstall watchman and still no dice.

npm install -g fsevents did not work for me npm install fsevents worked for me, optionally with -D flag

@LitoMore The reason being: https://github.com/facebook/jest/blob/ac267b16e46527d16945fe468f436e46c694fe73/packages/jest-haste-map/src/index.ts#L801

Jest Haste Map has a dependencies on SaneWatcher which can use FB Watchman over fs

// WatchmanWatcher > FSEventsWatcher > sane.NodeWatcher

Nothing helped until…

brew reinstall watchman fixed the problem on node v12.10.0

the fsevents and node-gyp packages have caused me issues for years, and it seems like nobody understands what actually causes this. i’m on mac os 10.15 but since mac os ~10.12 in like 2017 it’s thrown random errors and occasionally messed up npm installs just enough so that i have learned to try random crap until it sort of works without actually figuring it out.

here’s some things which have seemed to be related:

• messed up python 2 or pip install – sometimes this is helped by installing python 3.7 or 3.8 and aliasing python to python 3
• npm install -g node-gyp or npm install -g fsevents
• using npm instead of yarn or vice versa; deleting node_modules and reinstalling; deleting package-lock or yarn.lock and using the other one; etc.
• installing or reinstalling xcode command line tools, so that random .h files (frei0r.h is one of three which come up sometimes) which are in /usr/local/include get included by the clang++ compiler

i’ve shown these issues to people much smarter than me and nobody seems to be able to diagnose the problem. the fact that it sprawls between node, python and even c++ makes me think i’m just not going to figure this out and should just reinstall (although i haven’t actually had to yet).

i still have no clue what the central issue is, and whenever i google for related issues i just see threads like this with dozens of people saying “well i tried this and it worked i guess,” and eventually, replies like “that didnt work for me.” and many of them still get replies, like this one – the last reply was just 8 days ago.

if the above suggestions don’t work, reader, i wish i could help you.

edit: i’ve seen “try installing or reinstalling watchman” many times and although it clearly works for a lot of people, it’s one of the few suggestions that has never improved things for me.

edit 2: i switched to ubuntu because i like laptops with usb and hdmi ports. got a thinkpad and it installed in 15 minutes and i’ve actually had zero problems, never going back.

brew install watchman it might work if there’s no instance of watchman. In my situation, I had to brew upgrade watchman and it worked like a charm.

macOs: Catalina node: 12.12.0

brew reinstall watchman works for macOS Mojave, node v12.10.0

npm install -g fsevents worked for me.

brew install watchman didn’t work for me.

npm install --save-dev fsevents worked for me macOs: Mojave, node: 12.6.0

brew install watchman worked!!! Thanks.

brew install watchman worked for me also.

However, i stumbled across a non-related issue to do with excessive node process CPU usage when idle (~250%), and so i downloaded and re-installed Command Line Tools for Xcode, and then restarted my machine (that’s important), which appears to resolve the excessive node CPU usage issue, and by coincidence it looks to have also resolved the Jest Watch mode issue too, without the need for the brew dependency; watchman after i carried out a Jest Watch mode test run after uninstalling the dependency; brew uninstall watchman.

Not sure specifically why this approach to reinstalling Command Line Tools for Xcode works to resolve the Jest Watch mode issue as described on this ticket, which i had also suffered from.

But this may provide an alternative approach for others who may like to avoid installing additional dependencies such as watchman, where possible, to workaround the Jest Watch mode issue.

brew install watchman, this works!!

In my case all I needed was npm install 😃

brew upgrade watchman worked for me. I already had watchman installed, but upgraded from node 8 to node 10 and encountered this error.

@6220119 Thank you so much my Grabber! 🤝

Figured it out. I didn’t realise that Nuxt was putting a jest config into package.json, and for some reason, I had "watchman": false in there… sigh 😑

使用这个命令安装就好了 npm install --save-dev fsevents

brew install watchman didn’t work for me.

npm install --save-dev fsevents worked for me

macos: Big Sur Node version : 12

brew upgrade watchman worked for me as I already had it installed.

npm install fsevents fixed my issue as well. This is on a fresh install of mac osx

brew install watchman worked for me as well. Thanks.

I was facing this problem with version of node in 11.15.0, then I changed to v10.15.3 and its gone.

@EdouardBougon Those instructions worked for me, thanks!

No, 1.31.1 was just the latest vscode release