Incorrect hostname in terminal after factory reset I wiped out Mac and reinstalled (Mojave) (logout from Cloud, Messages, deauthorized iTunes, erase disk, reinstall). Now my terminal is showing a name that I set up through Preferences -> Sharing on previous instance of  system (before reinstall). 

I checked Preferences -> Sharing computer Name is:
Kathy’s MacBook Pro

When I check in bash:

red-panda:~ kathy$ scutil --get ComputerName
Kathy’s MacBook Pro
red-panda:~ kathy$ scutil --get LocalHostName
Kathys-MacBook-Pro
red-panda:~ kathy$ scutil --get HostName
HostName: not set


My questions:
1. Why red-panda is still there after reinstallation? Where that information is stored? If I want to sell the Mac, how can I be sure to wipe all out?
2. Can HostName: not set make any troubles?
1.) red-panda is your current computer name.


Click Apple Menu on Top Left
Open the System Preferences... App
Type Computer Name in Search
Change the red-panda to whatever you like, I would suggest something short, like KM, if you plan to use Terminal a lot
Close System Preferences... App




To securely wipe your hard drive, do an after-restart system reinstall and pick the proper option.

For more info and useful tips on how not to lose your own data before doing it, read some articles like this: 


What to do before you sell, give away, or trade in your Mac 
How to reset your Mac before selling it




2. No, no trouble for no hostname. The hostname is not set by default upon install.

However, if you wish to set it, execute: scutil --set HostName desired-hostname-here-again-I-suggest-a-short-name-like-kmp in Terminal.