Tinkering is all fun and games, until it's 4 am, your vision is blurry, and thinking straight becomes a non-option, or perhaps you just get overly confident, type something and press enter before considering the consequences of the command you're about to execute... And then all you have is a kernel panic and one thought bouncing in your head: "damn, what did I expect to happen?".
Off the top of my head I remember 2 of those. Both happened a while ago, so I don't remember all the details, unfortunately.
For the warmup, removing PAM. I was trying to convert my artix install to a regular arch without reinstalling everything. Should be kinda simple: change repos, install systemd, uninstall dinit and it's units, profit. Yet after doing just that I was left with some PAM errors... So, I Rdd-ed libpam instead of just using --overwrite. Needless to say, I had to search for live usb yet again.
And the one at least I find quite funny. After about a year of using arch I was considering myself a confident enough user, and it so happened that I wanted to install smth that was packaged for debian. A reasonable person would, perhaps, write a pkgbuild that would unpack the .deb and install it's contents properly along with all the necessary dependencies. But not me, I installed dpkg. The package refused to either work or install complaining that the version of glibc was incorrect... So, I installed glibc from Debian's repos. After a few seconds my poor PC probably spent staring in disbelief at the sheer stupidity of the meatbag behind the keyboard, I was met with a reboot, a kernel panic, and a need to find another PC to flash an archiso to a flash drive ('cause ofc I didn't have one at the time).
Anyways, what are your stories?
Found out the hard way that if you edit /etc/sudoers with anything other than visudo you best be absolutely sure the syntax is correct, otherwise sudo will refuse to read it and you'll be locked out.
Also learned to add -rf to the rm command at the end, after I re-read it to make sure it does what it should do. Something like rm /path -rf instead of rm -fr /path. That protects you from your fat fingers hitting the enter key half way through.
Been there with sudo. Fortunately,
sustill works, as well as going to another tty and logging in as root. Well, as long as the root login is enabled; otherwise that old hack withinit=/bin/bashmay work, unless you've prohibited editing kernel cmdline in the boitloader or decided on efistubIIRC the root account was disabled (with no password), so I resorted to my trusty SystemRescueCD pen to fix things. Never leave home without it.