Ubuntu – Why does apt removes unwanted packages when giving * as suffix?

Since no answer using apt has been found, I would suggest going into Synaptic Package Manager, click on the Status button at lower left then click on Installed (manual) at upper left to see a list of installed packages.

Then you can output a list from Synaptic with File | Save Markings As and save the file where you can work with it.

1. Boot to recovery then drop to shell

2. Check the network interfaces available.

   ifconfig -a
   

   If you don't see IP address (x.x.x.x), run DHCP query to get an IP, change eth0 with yours.

   dhclient eth0
   

3. Confirm connection

   ping -c3 ubuntu.com
   

   You should get an output similar to this:

   3 packets transmitted, 3 received, 0% packet loss
   

4. Check dpkg multi-arch setup

   $ dpkg --print-architecture
   amd64
   $ dpkg --print-foreign-architectures
   i386
   $ grep -ir arch /etc/dpkg/ 
   /etc/dpkg/dpkg.cfg.d/multiarch:foreign-architecture i386
   

   If i386 doesn't show up in 2nd & 3rd command, set it:

   echo "foreign-architecture i386" > /etc/dpkg/dpkg.cfg.d/multiarch
   

5. Update package list

   apt-get update
   

6. Run

   apt-get install ubuntu-desktop
   

7. If still getting "unmet dependencies" message, run aptitude.

   aptitude
   

   • Press / to search, write ubuntu-desktop then Enter
   • Then use n till ubuntu-desktop selected, NOT ubuntu-desktop:i386
   • + to flag it for installing

8. At this point, there should be a red bar at the bottom with number [1/..] which indication the current solution from many other possible onces.

   • Press e to examine, it show what the current solution is going to do.
   • Flip through all other solutions using ./,

   • You gonna see some solutions that prefer to keep installing packages without installing ubuntu-desktop. Choose the one that remove less and installs ubuntu-desktop.

     This is not always the perfect solution, so check well then choose. Each case is specific. For current case, see this related chat room.

   • ! to apply then g, check then g again to confirm.

9. If every thing goes OK, reboot.

10. Then install other need tools you need, which have been removed may be.

    Notes: These from my personal experience, so I could be wrong. So if anyone experienced otherwise, please share it.

    • Avoid installing .deb binary Debian packages locally using dpkg, debi or software-center. Use repositories as possible (Ubuntu ones, PPA, Other vendors ones,...).
    • For vendors packages, look for native architecture amd64. In rare cases building source (if available) is easier then foreign arch.

    • Software-center, synaptic, apt-get and many other tools, for me they not fully support multiarch feature. They show only 1 solution and (except apt-get) don't show the architecture of each package.

      If you face any conflict, use aptitude. It shows other solutions and shows clearly all packages from all available architecture.

    • If you have to install some i386 tools with no option for amd64. Leave them to be installed the last. If you have them already installed and you are trying to install native arch amd64 packages then you get a conflict (basically unmet dependencies message). Let aptitude uninstalls the i386 ones, then run clean up with apt-get autoremove to remove residues (auto-installed dependencies from i386 arch). Install amd64 packages you wanted then try installing back the removed i386 tools.

      Why is that? If you try to install a i386 tool, all its dependencies will be installed as i386 too, even amd64 ones available and can work. Later, if you try to install another amd64 tool which have at least one overlapped dependency, you get the conflict.

      Aptitude will seem like removing the packages, but actually it is replacing some i386 packages with the corresponding amd64 ones.

      See this show case, Ubuntu 14.04, problem when install gstreamer1.0-libav, unmet dependencies