I have Ubuntu MATE 20.04 installed in my computer. Somehow now apt is absolutely broken. Every package doesn't have an installation candidate.
Even worse, I can't download any package at all with Synaptic or aptitude. /etc/apt/sources.list seems perfectly fine.
[sudo] password for disablegraphics:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package fluid is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only
available from another source
E: Package 'fluid' has no installation candidate
disablegraphics@disablegraphics:~$ update-manager
Traceback (most recent call last):
File "/usr/bin/update-manager", line 28, in <module>
import gi
ModuleNotFoundError: no module named 'gi'
Sources.list part 1:
Sources.list part 2:
