$ nmap -sS
You requested a scan type which requires root privileges.
QUITTING!
$ sudo chmod +s /usr/bin/nmap
$ nmap -sS
Starting Nmap 7.80 ( https://nmap.org ) at 2019-11-21 19:07 HKT
WARNING: Running Nmap setuid, as you are doing, is a major security risk.

WARNING: Running Nmap setgid, as you are doing, is a major security risk.

WARNING: No targets were specified, so 0 hosts scanned.
Nmap done: 0 IP addresses (0 hosts up) scanned in 0.04 seconds