$ apt-get install -f -o 'Dpkg::Options::=--force-confmiss --force-all --force-confnew --overwrite-conffiles' --reinstall at-spi2-core
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 kde-workspace-bin : Depends: qdbus but it is not going to be installed
 libqt4-dbus : Depends: qdbus (= 4:4.8.5+git192-g085f851+dfsg-2ubuntu4) but it is not going to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

I don't quite understand "but it is not going to be installed". Why doesn't it install it then?

apt-get -f install does not help, it does nothing:

$ apt-get install -f
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
  • You could try to find out why qdbus is not being installed by installing it yourself: sudo apt-get install qdbus. – Jos Dec 22 '14 at 11:15
  • 5
    @Jos: I did that. Now it works. However, that doesn't really answer my question or what the problem was. – Albert Dec 22 '14 at 11:15
  • I suppose it was the combination of options in your original apt-get command that prevented apt from installing additional dependencies. – Jos Dec 22 '14 at 11:20
  • Here it was that I missed main and only had deb http://de.archive.ubuntu.com/ubuntu/ wily universe multiverse in addition to trusty. Then, apt wanted to install a package from universe, which depended on versions available in wily/main only and thus could not be installed. – koppor Jan 23 '16 at 14:45
  • 1
    Try adding the missing package to the install command: sudo apt-get install --reinstall at-spi2-core qdbus libqt4-dbus – antivirtel Apr 2 '16 at 20:58

This worked for me.

$ sudo apt-get install <missing-package-1> <missing-package-2> ...

I don't know why this is necessary, but manually installing the problematic packages worked.

After installing the first round of unmet dependencies, another one popped up, but I repeated the process and it sorted itself out after two cycles.

  • 14
    Wow, it really is this simple... It makes me wonder why it wouldn't install in the first place? – Jacksonkr Apr 19 '16 at 3:47
  • This helped me too, but had to run twice second time with reverse order of package names. Not sure if reversing order was necessary. – PeterM Apr 22 '18 at 16:17

As this question also didn't help, I found on this LinuxQuestions thread a hint that helped me:

Do you have a mixed /etc/apt/sources.list? It appears that you're trying to install one package from a newer repository but that it doesn't have access to a repository with the newer dependencies.

  • A mixed sources file, or maybe one with only a single repository but that has missing packages – golimar Mar 14 '18 at 13:22
  • I had the same problem - my sources.list had only the main repository and the dependency was somewhere else (universe, restricted, ...). The error message is very misleading. – WoJ Sep 20 '18 at 9:00
  • Yes, this is a possible reason. For example, ubuntu 20.04 with ubuntu 16.04 (xenial)'s sources.list, would make apt install xxx report similar problem. – HaxtraZ Nov 11 '20 at 10:49

I ran into this issue and solved it by running:

sudo apt-get update
sudo apt-get upgrade

Then when I ran the original "apt-get install" command succeeded.


I also had the same issue while installing Guake; it showed unmet dependencies with Python. Even trying to reinstall python using sudo apt-get install --reinstall python did nothing.


Step-1: I had to remove and install python again using:

Note: Uninstalling python leads to removing many other dependencies which may break the installed Ubuntu, so be careful while uninstalling python

sudo apt-get purge python

sudo apt-get install python

Step-2: Install the original package (in my case it was guake)

sudo apt-get install guake

This installed all necessary dependencies.

Try the same procedure w/ your packages and it should work for you too.

  • 2
    Removing Python, even only temporarily, is a bad idea as it will likely remove lots of depending packages with it and it is needed to run many important system commands. – Byte Commander Sep 14 '17 at 20:03
  • I was aware of this possibility but i wasn't able to solve my issue otherwise....searched a lot but could not find a working way....as of now my ubuntu has not broken ..... waiting for it in future ;) ... – imflash217 Sep 14 '17 at 20:48

Nothing above worked for me but following procedure saved me

sudo dpkg --configure -a 

this will list the broken packages and

sudo dpkg -r librrd4 

{librrd4 and libpng12 were my broken pakages solved the problem


I had similar problems with cups-filters on raspberrypi caused by realvnc-vnc-server. It was due to foomatic-filters being deprecated. I couldn't install or uninstall anything so what worked for me was to delete the apt cache for cups-filters.

sudo rm /var/cache/apt/archives/cups-filters*

Then the install worked as suggested by @funroll

sudo apt install cups cup-filters


In my case it needed the version of the package from focal, but it wanted to install the version from focal-updates. On theory it can be fixed by running apt-install pkg_name_here=older_specific_version_here. In my specific case that wasn't acceptable because i had many packages depending on the newer version of one of the nested dependencies which it wanted to remove along the downgrade, so i said no.

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