I needed to upgrade libc6 from 2.27 to 2.31, but it was not working with apt-get install
(it claimed 2.27 is the newest version which is not true) so as suggested by this thread I've downloaded deb package of libc6 and ran:
sudo dpkg -i --auto-deconfigure libc6_2.31-9_amd64.deb
it threw some errors about incorrect dependencies, but after that I could not do anything because when using sudo
it started to throw: sudo 3 incorrect password attempts
every time (even though I did not enter any password).
At this point, with lack of other options I just rebooted the PC hoping it will fix itself, but now the system is stuck in some kind of loop, the screen is blinking all the time as it tries to start and I cannot do anything at all.
I guess the only way out of this is by using Recovery Mode, but which option should I choose?