Troubleshooting Ubuntu and other general issues

Table of contents

  1. “username is not in the sudoers file”
  2. E: Unable/Failed to fetch some archives

“username is not in the sudoers file”

Many operations in UNIX require super user (sudo) permissions. Without these permissions, you might see:

<username> is not in the sudoers file. This incident will be reported

Run the following commands:1

$ su
$ password: <password of your VM>
$ usermod -aG sudo <username>

Restart your VM, and try the command again.

E: Unable/Failed to fetch some archives

apt is a package manager and relies on online archives that point to the source of these packages. You may run into this error when attempting to install via sudo apt installl or when upgrading packages with sudo apt upgrade:

Failed to fetch ...
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

You should update the package references via:

sudo apt-get update

It’s best to install using sudo apt-get install <name> as apt-get achieves a multitude of actions.2

  1. sudoers file fix from Stack Overflow ↩

  2. Explanation of apt-get from Ask Ubuntu ↩