extjssencha-cmd

Error "User limit of inotify watches reached". ExtReact build

I installed ExtReact, with examples. When I run

npm start

I get an error: 

ERROR in [@extjs/reactor-webpack-plugin]: Error:
[ERR] BUILD FAILED
[ERR] com.sencha.exceptions.BasicException: User limit of inotify watches 
reached
[ERR]
[ERR] Total time: 13 seconds

[ERR] /home/user/project/build/ext-react/build.xml:101: 
com.sencha.exceptions.BasicException: User limit of inotify watches reached
[ERR] A log is available in the file "/home/user/project/build/ext-
react/sencha-error-20171027.log"

How to fix this error?

Solution

  • Why?

    Programs that sync files such as dropbox, git etc use inotify to notice changes to the file system. The limit can be see by -

    cat /proc/sys/fs/inotify/max_user_watches

    For me, it shows 100000. When this limit is not enough to monitor all files inside a directory it throws this error.

    Increasing the amount of inotify watchers(Short version):

    If you are running Debian, RedHat, or another similar Linux distribution, run the following in a terminal:

    echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p

    If you are running ArchLinux, run the following command instead (see here for why):

    echo fs.inotify.max_user_watches=524288 | sudo tee /etc/sysctl.d/40-max-user-watches.conf && sudo sysctl --system

    Then paste it in your terminal and press on enter to run it.

    Technical details:

    Listen uses inotify by default on Linux to monitor directories for changes. It's not uncommon to encounter a system limit on the number of files you can monitor. For example, Ubuntu Lucid's (64bit) inotify limit is set to 8192.

    You can get your current inotify file watch limit by executing:

    cat /proc/sys/fs/inotify/max_user_watches

    When this limit is not enough to monitor all files inside a directory, the limit must be increased for Listen to work properly.

    You can set a new limit temporary with:

    sudo sysctl fs.inotify.max_user_watches=524288
sudo sysctl -p

    If you like to make your limit permanent, use:

    echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

    You may also need to pay attention to the values of max_queued_events and max_user_instances if Listen keeps on complaining.

    Source: https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers