Jest: No output in macOS Sierra Developer Beta 8

[inyono]

Do you want to request a _feature_ or report a _bug_?
Bug

What is the current behavior?
In the getting started example, npm test runs an infinite time w/o any output:

npm test

> @ test /Users/inyono/Projects/jest/examples/getting_started
> jest

While ./node_modules/.bin/jest --help works as intended, ./node_modules/.bin/jest --version also hangs w/o any output. Terminal says watchman is running.

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal repository on GitHub that we can npm install and npm test.

1. git clone [email protected]:facebook/jest.git
2. cd jest/examples/getting_started
3. npm install
4. npm test

What is the expected behavior?
As described in https://facebook.github.io/jest/docs/getting-started.html

Run Jest again with --debug and provide the full configuration it prints. Please mention your node and npm version and operating system.

• npm test -- --debug resp. ./node_modules/.bin/jest --debug hang w/o any output
• npm 3.10.3
• node v6.5.0
• [email protected]
• OS: macOS Sierra Developer Beta 8

[cpojer]

Unfortunately I don't have access to the new version of macOS yet. Do you have some time to help troubleshoot and potentially fix the issue? See https://github.com/facebook/jest/blob/master/CONTRIBUTING.md#worfklow-and-pull-requests for how to get started.

Can you try --no-watchman to see if this is a watchman issue?

[inyono]

Thanks for the quick response.

--no-watchman didn't help, Terminal still says that watchman is running. I will try to troubleshoot the issue.

[cpojer]

It probably makes sense to console.log in this promise chain: https://github.com/facebook/jest/blob/master/packages/jest-cli/src/jest.js#L133 and see where it gets stuck.

If you are using the Jest repo itself, make sure you do npm run watch in a background tab to keep compiling your files. You can also just insert those logs into the build file of jest in your project.

[inyono]

Thanks for the pointers, seems to be an issue with watchman. Jest hangs here: https://github.com/facebook/jest/blob/master/packages/jest-haste-map/src/index.js#L73. This is also the case when I run watchman version directly in the terminal (no output). watchman -v works, though, and outputs 4.6.0. I installed watchman using homebrew.

[inyono]

Fun fact: If I uninstall watchman, jest works again 😄

[cpojer]

@wez are there any known problems with watchman on macOS Sierra?

[wez]

I've not had any reports of problems on macOS Sierra so far, but have not tried it for myself yet. It would be valuable to get a copy of @inyono's watchman logs. I believe that they are located in /usr/local/var/run/watchman/$USER-state/log for a homebrew install. Would be great to get that in a gist or pastebin or something.

[inyono]

@wez There were logs at the location you mentioned. The last entries are from a month ago using watchman v4.5.0:

2016-08-01T14:50:06,518: [listener] Watchman 4.5.0 <no build info set> starting up on Jonass-MacBook-Pro.local
2016-08-01T14:50:06,523: [listener] Using watcher mechanism fsevents
2016-08-01T14:50:06,524: [listener] file limit is 256 kern.maxfilesperproc=10240
2016-08-01T14:50:06,524: [listener] raised file limit to 10240
2016-08-01T14:50:06,524: [listener] Using socket from launchd as listening socket
Terminating due to signal 15 Terminated generated by pid=1 uid=0.  (0x0)
0   watchman                            0x0000000103127b0f crash_handler + 345
1   libsystem_platform.dylib            0x0000000103db7d7a _sigtramp + 26
2   ???                                 0x0000000000000000 0x0 + 0
3   watchman                            0x00000001031363ce run_service + 216
4   watchman                            0x000000010313624a main + 2465
5   libdyld.dylib                       0x0000000103a7c255 start + 1

There are no logs for watchman v4.6.0, though, even when trying to run watchman. So I suppose that watchman v4.5.0 worked fine but there is some problem with v4.6.0. I can't downgrade to the previous version using brew, unfortunately. If it helps, I can try to build v4.5.0 manually again and try if this works as intended.

[cpojer]

It seems like this is a watchman issue because Jest works fine if watchman isn't installed. I opened an issue on the watchman bug tracker but happy to reopen here if it turns out to be a Jest issue.

[inyono]

Agreed. The only "issue" I see on Jest's side is that --no-watchman succeeds after the canUseWatchman check and is therefore useless when watchman version goes into an infinite loop.

[wez]

This turned out to be one of the watchman shutdown issues in 4.5 that got fixed in 4.6

[wez]

also: I reached out to our most active engineer currently running macOS Sierra and our watchman diagnostics ran clean. It's a small sample size, but I think we can rule out a Sierra specific issue here.

[mdtusz]

For future readers: I have seen this same issue on El Cap 10.11.6 with jest 13.2.3, but uninstalling watchman (4.7.0) seems to fix it.

[wez]

@mdtusz perhaps you hit https://github.com/facebook/watchman/issues/358 instead?

[hawkrives]

I'm on Sierra, [email protected], and [email protected], and tried the things listed in here:

• watchman -v: 4.7.0
• watchman version: hangs
• jest --help: prints help message
• jest -v: hangs, never prints anything
• jest: hangs, never prints anything
• jest --no-watchman: hangs, never prints anything

After uninstalling watchman, jest works correctly.

I apologize if this would be better served reporting on some other issue / repo.

[inyono]

Had this problem again, too. https://github.com/facebook/watchman/issues/355 helped again