Cannot Start Jekyll at Specific Port

By Amr

Handle error ‘Address Already in Use’ when starting Jekyll.

Estimated reading time: 1 minutes

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Handle error ‘Address Already in Use’ when starting Jekyll.

1. Issue of ‘Address Already in Use’

I’ve set up my GitHub Page website locally. It works as expected. But sometimes, I’m unable to start Jekyll. I keep getting the following error after running ‘jekyll serve’ command.

jekyll 3.5.2 | Error:  Address already in use - bind(2) for

Port 4000 has already been occupied. To solve this issue, kill the process that is using this port.
Find the process which is using port 4000.

sudo lsof -i :4000

Kill the process with its id.

sudo kill -9 <PID>


Retry ‘jekyll serve’, the error ‘Port Already in Use’ is gone.

2. NoMachine Process

Similar problem - Port 4000 is occupied by NoMachine(nxd).

Johnny@Johnny-Mac:~$ sudo lsof -i :4000
nxd     11199   nx    3u  IPv4 0x2fad2a11645a3de5      0t0  TCP *:terabase (LISTEN)
nxd     11199   nx    4u  IPv6 0x2fad2a115cded5bd      0t0  TCP *:terabase (LISTEN)

Killing the thread won’t work, because NoMachine’s nxd process will keep restarting, with a new PID. Either you have to change the port for your app. Or, change the service port for NoMachine. NoMachine->Preferences->Connection preferences. image

We can also shutdown NoMachine and disable the automatic start at next boot via command line.

On Linux:

sudo /etc/NX/nxserver --shutdown
sudo /etc/NX/nxserver --startmode manual

On Mac:

sudo /etc/NX/nxserver --shutdown
sudo /etc/NX/nxserver --startmode manual

On Windows: Open the CMD console as administrator and move to the bin folder under the NoMachine installation directory and run:

nxserver --shutdown
nxserver --startmode manual

3. References