Damn! I locked myself out of my new Linux System!

I was re-installing my Linux laptop, using Fedora KDE spin (if that matters). For various reasons, I haven’t noticed that the main account, the one used for myself, was created with an incorrect username of lferrariluca instead of the usual and simple luca I use. And of course, as usual in these automated installations, the root account was disabled. When installation finished, and I rebooted my machine, I fired up my terminal just to find out the wrong username placed into the system. Ok, time to fix this, how hard can it be? Well, it turned out that, while it is still a simple task, it was not so simple as it seemed. There is a correct way of doing this, and a wrong one. The correct way is to use usermod, but I’m used to FreeBSD pw, so in a rush I was not thinking about this tool and, having yet no internet connection, I had to do this by myself. So I edited /etc/passwd and /etc/shadow to rename the account into the right string. And bam! I got locked out, because I had no chance to use sudo(1) anymore. Clearly I forgot to edit the /etc/group file too, and since I closed the privileged session, I was no more able to edit anything. Luckily, I still had the USB stick to start a rescue session, so I had to boot a live system, mount the root filesystem (that now is stored literally under a /root directory on the partition) and edit /etc/group within it. At least, Fedora uses the well established sudo rules where wheel members can become superusers, so it turned out that changing the wheel entry in /etc/group fixed everything. This is a great trip back in the days where sysadmins were doing all this stuff by hands, and clearly nothing was in sync!