sudo on Windows 10 Linux subsystem cannot resolve local machine name

I installed Windows 10 Anniversary update and the Linux subsystem. When running anything with sudo it takes ages and then I get this error message:

sudo: unable to resolve host MYMACHINE

How to get rid of this and make sudo fast?

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