How do I overcome these package dependency problems?

Question

I upgraded to 11.10 and lost power during the upgrade. After bringing the box back up, I attempted to continue the upgrade and at one point did a partial upgrade to resolved dependency issues that I thought at the time were related to may failed upgrade. Now I have a working system for the most part. The problem is I can not install the 'acroread' package anymore because of dependency errors:

~ $ sudo apt-get install acroread

Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:

The following packages have unmet dependencies: acroread : Depends: nspluginwrapper but it is not going to be installed E: Unable to correct problems, you have held broken packages.

~ $ sudo apt-get install nspluginwrapper`

Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:

The following packages have unmet dependencies: nspluginwrapper : Depends: nspluginviewer (= 1.4.4-0ubuntu3) E: Unable to correct problems, you have held broken packages.

 ~ $ sudo apt-get install nspluginviewer

Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:

The following packages have unmet dependencies: nspluginviewer:i386 : Depends: libgtk2.0-0:i386 (>= 2.8.0) but it is not going to be installed E: Unable to correct problems, you have held broken packages.

I am running 64-bit but it seems acroread needs some 32-bit libraries that are not able to be installed. In my reading, I've found that there were some changes to multi-arch packages.

Does anyone know how I can repair my system to get around this problem?

Answer 1

Try sudo apt-get install -f. It will probably give some suggestions about removing and installing packages, do what seems reasonable. If that doesn't help, try booting into recovery mode and choosing the "fix broken packages". If that doesn't work... I don't know, I'd reinstall Ubuntu if I were you. (This is a good reason to always have /home on a separate partition!)

Answer 2

The latest release added multiple architecture support. 32 bit libraries are added as 32 bit libraries. I suspect you need to install the ia32-libs-multiarch. Try these commands:

sudo apt-get install ia32-libs-multiarch:i386
sudo apt-get check

Caught me by surprize. Also I found aptitude hasn't been updated to support the change.

Answer 3

You need to enable multiarch before attempting to install 32 bit libs:

 echo foreign-architecture i386 | sudo tee /etc/dpkg/dpkg.cfg.d/multiarch

After doing so, you should then be able to install whatever 32 bit libs you need.