Unable to resolve Host - Windows Bash

You can fix this by adding an entry to your /etc/hosts for your machine's hostname.

If you want a one-liner, something like this will do it:

printf "\n127.0.0.1   $HOSTNAME\n" | sudo tee -a /etc/hosts

This will append a line to your hosts file that will resolve the current hostname to 127.0.0.1.

When you run the command above you'll be prompted for the root password you set when the Windows Linux subsystem was installed. Also, since this command starts a shell for the root user just before it runs you'll actually see the sudo: unable to resolve host WHATEVER message one last time just before the change is made.

Alternatively, you run an editor (such as nano) as root and add the entry manually:

sudo nano /etc/hosts