OS X Catalina: add user to sudoers

It turns out that even an admin user needs to use sudo to edit the sudoers file at /private/etc/sudoers so the following did the trick to open the file for edit:

$ sudo visudo /private/etc/sudoers

As usual, a user can be added to the list of sudoers by adding a line such as this:

username ALL=(ALL) ALL

If you want to be able to use sudo without typing a password:

sudo visudo

And add:

username        ALL = (ALL) NOPASSWD:ALL

Adding this gives any commands, including scripts, you execute in the terminal ability to run sudo without a prompt, which exposes you to increased risk of exploitation. Use with caution.