Comment 35 for bug 1688721

   So far, the solution has been to apply
          sudo dpkg --configure -a
          sudo apt --fix-broken install
          sudo dpkg --configure -a

Which doesn't seem like something that will bring happiness to anyone.
     But the worst is that these solutions have not worked for everyone. A lot of people gave up and had to reinstall. I was left out, for example, and I was killing myself with this problem until I almost reincarnated. I'm sure when I die, I'll be canonized...

  I found ! I found the problem (and a better solution than what the veterans have recommended): Manually installing gconf2-common via dpkg -- which is normally considered dangerous and not recommended because of the risks. dconf2-common is definitely bugged, but it's not empty or false bug reports as some veterans and developers have said out there -- it's much more serious : The configuration is incomplete and errors go up to initramfs, which accumulates errors, until installation break. this accumulation even prevents the complete and correct installation of packages in the following updates, and these errors also go up to Initramfs, in a vicious circle that ends up breaking the installation. And the unfortunate gconf-service-backend and gconf-service have a circular dependency between them. In short, gconf is all shit by sheer sloppiness of the developer. A mistake is fine, but 2, including circular dependency is just plain sloppiness, really, indefensible! The difficulty here is "Dreadful" level. But I've had a lot of practice installing packages by hand, since the time of the legendary Build-Essential bug in Trusty Tahr, which broke the system every time you tried to install the damn thing, and took 2 years to solve... challenge, and I had to download all the packages by hand and install them one-by-one, in order of dependencies, until I found the bugs. More than 20 depes... At the time, the bugs were, for example: a circular dependency on libc++-6-dev, and a dependency on it that was rotten and had to install the Lucid version, a brutal downgrade, 2 versions below. It was a school! I applied the same method here, although I don't miss the thing at all. The trick itself is to download the dependencies and place them in individual numbered folders, following the order they were installed in the dependency chain, and then open a terminal in each one and apply the dreaded "sudo dpkg --force-breaks -i *". This option is very dangerous, and it takes a lot of marijuana to face this adventure... So I first test with the "sudo dpkg -i *" version to see if there are any other pending dependencies. When approved, then yes, I reinstall with the option sudo dpkg --force-breaks -i * to ensure the package configuration without false or "semi-false" error warnings (which look fake, but generate errors in the initramfs ). The package gconf2-common can only be installed by this option in a folder ONLY with it. Otherwise, it is unconfigured, and it fucks all dependents of it that comes after... The option * should install all the packages that are in the folder together. But the new version of dpkg has one of those security features of dubious utility, which allows you to install a maximum of 3 depes together at once with this option (using the * replaces the package name -- instead of typing each name one- by one, with risk of error, we use *, in place of the name of the packages and dpkg installs all the dependencies that are in the folder ). Then you have to install gconf-service-backend and gconf-service TOGETHER in the same folder, folder 2, BECAUSE IT HAS CIRCULAR DEPENDENCE, and it is only possible to install circular dependency without breaking with "sudo dpkg --force-breaks - i *" and installed both together at the same time. Finally, in a third folder and with a third terminal, we install gconf2. If after all this installation you test with "sudo dpkg --configure -a" in a terminal, there is no response back, because there is no more configuration of pending files.

    Well, that's all (Whew...) but the really bad thing is that you can't do it in a virtual machine, you have to risk your neck. Why ? Because this type of bug, like many others, tends not to happen with a fresh install, just a few updates after installing gconf2-commom bugs. If you install everything in one session, no problem, but after you update dpkg and restart the machine, the new version of dpkg -- much more error intolerant -- bugs gconf2-common... That's why I said it was the developer's unforgivable sloppiness: He wrote the package triggers for the system's native install dpkg version (the install CdRom) but not for the working version, the current version of dpkg. So, on the first update, it fucked up!

    An eternal classic of this type of error, are the appimage packages, WHICH DOES NOT WORK IN LINUX MINT after some updates... They are simply not recognized as executables, no matter how much you change or reset the permissions... Probably some silly update from libc6...