Start script hangs without error when there are no available inotify watches

Description

I tried to run npm start in a new project (i.e. I ran the four commands under “Quick Overview”), and it hanged indefinitely (well, at least for several minutes until I aborted) after the output “Starting packager…”.

Running react-native start gave the error ERROR watch {path} ENOSPC, which made me realize that there were no available inotify watches.

After increasing fs.inotify.max_user_watches, npm start started and ran normally.

Expected Behavior

npm start should give a warning or exit with an error saying that there are no available watches, so it can’t start.

Observed Behavior

npm start hanged with this output, and never continued:

$ npm start

> my-app@0.1.0 start /home/trygve/dev/create-react-native-app/my-app
> react-native-scripts start

13.49.26: Starting packager...

Environment

Please run these commands in the project folder and fill in their results:

• npm ls react-native-scripts: react-native-scripts@0.0.30
• npm ls react-native: react-native@0.44.2
• npm ls expo: expo@17.0.0
• node -v: v7.10.0
• npm -v: 4.6.1
• yarn --version: 0.24.6
• watchman version: Not installed

Also specify:

1. Operating system: Arch Linux
2. Phone/emulator/simulator & version: Not relevant

Reproducible Demo

Ran npm start in a clean project just created, so nothing to provide here.

[darkguy2008]

I also have the same issue, using OSX Sierra 10.12.5. sysctl returns sysctl: unknown oid 'fs.inotify.max_user_watches'. Any ideas? 😦 I can’t start up any react iOS app, the simulator does, but nothing else happens and it gets stuck in the Packager thing…

Nevemind, fixed it with this:

sudo sysctl -w kern.maxfiles=524288
sudo sysctl -w kern.maxfilesperproc=524288

[k3a]

@tetralix On Linux do “sudo sysctl -w fs.inotify.max_user_watches=10000”. This changes kernel sysctl value. This is temporary until reboot. To make it permanent, add fs.inotify.max_user_watches=10000 to a file in /etc/sysctl.d directory or /etc/sysctl.conf depending on distro.