Love to have nmap on my #raspberrypi, but:
root@qwers:/home/pi# apt-get update
Hit:1 http://archive.raspberrypi.org/debian stretch InRelease
Hit:2 https://deb.nodesource.com/node_9.x stretch InRelease
Reading package lists... Done
root@qwers:/home/pi# apt-get install nmap
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package nmap
apt-cache search nmap
has no result:- and
/etc/apt/sources.list: No such file or directory
Went trough these steps without any result: apt - "E: Unable to locate package update" when I try to update my system, why? - Ask Ubuntu
Ended up here to: Apt "could not find a distribution template" error - Ask Ubuntu with the result of:
aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for Raspbian/stretch