sudo error unable to resolve host locahost (using linuxdeploy on android device)

So I installed linuxdeploy on my phone to mess around with a debian linux. Installed debian 9 for arm64 and so far so good. Only when I run any "sudo" command, I'm getting the following warning: sudo: unable to resolve host localhost: no such file or directory (I still get the root access though) I've been looking on the web but did not find anyone with his exact error message. I checked the following files: /etc/hosts, it contains 1 line: 127.0.0.1 localhost /etc/hostname, it contains 1 line: localhost Edit: as per asked in the comments below, I tried to run the command: grep hosts /etc/nsswitch.conf resulting in: no such file or directory A quick look at /etc folder indeed shows that this file is missing