Listen error unable to monitor directories for changes



problem

FATAL: Listen error: unable to monitor directories for changes.  
Visit https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers  
for info on how to fix this.

This problem is mount of inotify watchers.

What is Inotify? https://en.wikipedia.org/wiki/Inotify

Inotify (inode notify) is a Linux kernel subsystem that acts to extend filesystems to notice changes to the filesystem, and report those changes to applications. It replaces an earlier facility, dnotify, which had similar goals.
One major use is in desktop search utilities like Beagle, where its functionality permits reindexing of changed files without scanning the filesystem for changes every few minutes, which would be very inefficient.

Inotify can also be used to automatically update directory views, reload configuration files, log changes, backup, synchronize, and upload.

We have to increase mount!!

solve

You can find this solution in this link. https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers

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.