sudo on Windows 10 Linux subsystem cannot resolve local machine name

You have to edit /etc/hosts while superuser and add your machine name after the first line with localhost

127.0.0.1        localhost MYMACHINE

This will make the system not try to resolve the hostname from DNS.

You can also remove /etc/hosts and restart bash to generate a version that contains your hostname. For me, it created a line with my computer name and my fully qualified name 127.0.0.1 fbc-2000.domain.local fbc-2000