[5.7.4] Notebook Crash when launched with ip="*"

[ZijiaLewisLu]

Hi,

I updated my jupyter notebook to 5.7.4 today and I found it crashed when I set ip="*" (either from the command line or config file).

I found it was because the "self.ip" attribute in NotebookApp object somehow became an empty string and triggered error while calling socket.getaddrinfo. Anyway to fix it?

This is the error I got:

I printed "self.ip" in the error line. It was an empty string.