Error: watch /var/www/shards/public ENOSPC

FIX ENOSPC YARN

ERROR:
yarn run v1.12.3
$ vue-cli-service serve
 INFO  Starting development server...
 10% building modules 1/1 modules 0 activeevents.js:183                              
      throw er; // Unhandled 'error' event
      ^

Error: watch /var/www/shards/public ENOSPC
    at FSWatcher.start (fs.js:1382:19)
    at Object.fs.watch (fs.js:1408:11)
    at createFsWatchInstance (/var/www/shards/node_modules/chokidar/lib/nodefs-handler.js:37:15)
    at setFsWatchListener (/var/www/shards/node_modules/chokidar/lib/nodefs-handler.js:80:15)
    at FSWatcher.NodeFsHandler._watchWithNodeFs (/var/www/shards/node_modules/chokidar/lib/nodefs-handler.js:232:14)
    at FSWatcher.NodeFsHandler._handleDir (/var/www/shards/node_modules/chokidar/lib/nodefs-handler.js:414:19)
    at FSWatcher.<anonymous> (/var/www/shards/node_modules/chokidar/lib/nodefs-handler.js:462:19)
    at FSWatcher.<anonymous> (/var/www/shards/node_modules/chokidar/lib/nodefs-handler.js:467:16)
    at FSReqWrap.oncomplete (fs.js:153:5)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

SOLUTION:

From my findings its not related to Jest at all. On Linux (or Mac) we have a max number of system watchers we can place at an IO level (from my understanding). So for large projects, it seems that Jest is trying to watch just way to many files.

To fix:

echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p
Source: Node.JS Error: ENOSPC