Comment 1 for bug 1129464

While we should pin the version of grunt (the .3/.4 APIs are different) the error that you posted to IRC seemed to be related to an issue with a known work-around.

Adding a file/line to sysctl to expand the inotify watch limit will mask the issue with node.

 cat /etc/sysctl.d/10-inotify.conf
# expand inotify limit
fs.inotify.max_user_watches=16384