I've just tried to install Linode's Longview on a new Custom VPS set up through Forge. (I've done about 10 times before without issue.) I attempted to run the command…
Are you still listed in the sudoer group as indicated above? Log out and log back in to check for changes. You can also try to boot into recovery mode and root then usermod -a -G sudo forge Or
- boot system into recovery mode
- `mount -rw -o remount /` or if you get to choose root user first and then enter this command
- Goto `root` user
- `usermod -a -G sudo forge`
- `reboot`
You can only use the above process if you have access to the boot process so no SSH.
Thanks for the advice @ejdelmonico - I think I might just get the provider to reinstall the VM: I don't have enough access to the host to boot into recovery mode. If that's not working then other parts of the install might be broken that I discover later!
Useful commands though, should I need them in the future!