Pelican restarting you server
When you press Ctrl + C or Ctrl + z, do not restart the HTTP server: it is running in the background, and that is the exact reason as why you are getting that error message. 
To see that the server is running in the background after pressing the any of the key combinations above, try to edit and save any file: you will see right away in the terminal the re-generation process of your pages is active again.
You can start the HTTP server using this command: make devserver and stop by ./developer_server.sh stop
Hi I just started working with Pelican and it really suits my needs, I had tried to build blogs in Flask and other frameworks but I really just wanted something simple so I can post about math, and pelican just works.
My question is when I am testing on my machine, I start the server; however when I stop the server to make some edits to my test blogs, and then try to reload the server I get a socket already in use error.  I am stopping my server by ctrl+z am I doing this correctly?