File Limits

Hot reloading uses native file watching features of unix-compatible systems. This is extremely handy and efficient, but unfortunately most systems have very low limits on watched and open files. If you use hot reloading a lot, you should expect to see: Error: watch EMFILE or similar.

To solve the problem you need to raise your filesystem limits. This may be a two-step process. On Linux, there’re hard limits (something root user can change in /etc/limits.conf or /ets/security/limits.conf) that govern the limits individual users can alter from command-line.

You should probably putulimit -n 10000in your .profile file, because it does not persist between restarts.

For OS-X and Solaris-specific instructions see a Stackoverflow Answer​