How I broke sudo on my Dads Mac and how I fixed it

Currently, I’m in the process of migrating my Steam Deck to NixOS. Today finally arrived my 1 TB NVMe, so I rushed to installing it and reinstalling NixOS as I already had a working configuration. The annoying part is, that, when using Jovian-NixOS you need to compile the kernel. As this takes long and my father owns a M1 Mac, I thought about building my NixOS configuration on the mac and copying it to the Steam Deck.

The Problem

I then installed Nix on the Mac and got everything working, but as I wanted to build my NixOS Configuration on the Mac, the build failed. It failed, because I couldn’t enter the sudo password. After much browsing the web, I wanted to make sudo passwordless. So I open visudo and changed

%admin ALL=(ALL) ALL

to

%admin ALL=(ALL) :NOPASSWD ALL

Do you see the mistake? It’s the wrong place column. But I was in a rush, saved the file, wanted to test out my new fancy passwordless sudo by running sudo echo test and got greeted by a alex is not in suderos file.

The Journey begins

Try 1

I tried out the here described “Finder” solution but failed. I just couldn’t change the permission back. An hour later, I moved on to recovery mode.

Try 2 — Recovery Mode, my savior

So, I finally booted into recovery mode, and logged in. Then mounted the Data disk via the disk utility program.
Now I could open a terminal, navigate to /foo/bar/etc and repair the file permission while also fixing the typo.

What I’ve learned

1. If visudo asks you if you really want to save the File, don’t blindly type yes!
2. root is your friend

I would love to hear about your funny tech fails. Just send me an email.