[Trisquel-users] Broken/missing packages

[apvp at hush.ai]

This isn't the first time... I have just re-installed Trisquel 5.5 on my  
laptop and when i tried to install some additional software from the  
repositories my crappy ultra-mega-slow internet connection kept failing and  
the result is a whole bunch of broken packages and many dependencies missing.

It isn't the first time, when installing additional packages, that if that  
installation is abnormally interrupted it also messes with already installed  
software making them "magically" disappear. Brasero, Totem, GIMP, and who  
knows what else (many more) simply vanished from my computer.

Now i can't install anything from the menu "Add/Remove applications" (it  
doesn't even start, regardless of how good the internet connection is) and  
the menu entry that allowed me to edit the system's settings disappeared!  
Also, when i try to bring synaptic's GUI up from the command-line i get this:  
No protocol specified

(synaptic:27837): Gtk-WARNING **: cannot open display: :0.0.

Please don't tell me i have to reinstall Trisquel for the Nth time... Is  
there something i can do?