How do I install 32-bit libraries when they keep having uninstallable dependencies?

Question

I'm trying to install Adobe Air on Ubuntu 13.10. In this version of Ubuntu, packages like ia32-libs and ia32-libs-multiarch are no longer available, so I'm trying to install the needed 32-bit libraries on my own. When running ./AdobeAIRInstaller.bin I got several errors about missing libraries, most of which I managed to install using sudo apt-get install <library-name>:i386 and the errors went away. I'm having issues fixing the last two missing modules though:

Gtk-Message: Failed to load module "overlay-scrollbar"
Gtk-Message: Failed to load module "unity-gtk-module"

I tried installing overlay-scrollbar-gtk2:i386 using apt:

overlay-scrollbar-gtk2:i386 : Depends: overlay-scrollbar:i386 but it is not installable

Well darn, it depends on a package that can't be installed. How inconvenient. So I tried Googling my way forth to the 32-bit overlay-scrollbar libraries for Saucy, which I found here. First I installed overlay-scrollbar:

$ sudo dpkg -i overlay-scrollbar_0.2.16+r359+13.10.20130826-0ubuntu1_all.deb 
(Reading database ... 226507 files and directories currently installed.)
Preparing to replace overlay-scrollbar 0.2.16+r359+13.10.20130826-0ubuntu1 (using overlay-scrollbar_0.2.16+r359+13.10.20130826-0ubuntu1_all.deb) ...
Unpacking replacement overlay-scrollbar ...
Setting up overlay-scrollbar (0.2.16+r359+13.10.20130826-0ubuntu1) ...
Processing triggers for libglib2.0-0:i386 ...
Processing triggers for libglib2.0-0:amd64 ...

Great! It worked. Then I tried installing overlay-scrollbar-gtk2:i386:

$ sudo dpkg -i overlay-scrollbar-gtk2_0.2.16+r359+13.10.20130826-0ubuntu1_i386.deb 
Selecting previously unselected package overlay-scrollbar-gtk2:i386.
(Reading database ... 226507 files and directories currently installed.)
Unpacking overlay-scrollbar-gtk2:i386 (from overlay-scrollbar-gtk2_0.2.16+r359+13.10.20130826-0ubuntu1_i386.deb) ...
dpkg: dependency problems prevent configuration of overlay-scrollbar-gtk2:i386:
 overlay-scrollbar-gtk2:i386 depends on overlay-scrollbar.

dpkg: error processing overlay-scrollbar-gtk2:i386 (--install):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 overlay-scrollbar-gtk2:i386

So apparently I still need to install overlay-scrollbar:i386, which is not installable by apt and didn't get installed by the installer above. My issues with unity-gtk-module are pretty much identical but with different package names.

I have a couple of very related questions regarding this:

• Why are some very important 32-bit packages not installable using apt? Am I missing a source?
• Why didn't the i386 version of overlay-scrollbar get installed above? Is it because the installer contains both 32-bit and 64-bit versions of the library and automatically decided to install just the 64-bit one on my system? Can I force it to install both?

Answer 1

apt-get download overlay-scrollbar-gtk2
sudo dpkg --ignore-depends overlay-scrollbar -i overlay-scrollbar-gtk2*.deb

Simple.

This will work, if you've already installed package for your architecture. If not, you will get errors, while trying to use dpkg/apt-get next time. To fix them, run:

sudo gedit /var/lib/dpkg/status

Find Package: [package name, overlay-scrollbar-gtk2 in this case], and remove ignored dependencies from Depends: (overlay-scrollbar in this case).

If you use gedit, make sure you've disabled automatic backups in Edit > Preferences > Editor before saving. Notice that gedit has seperate preferences for each user, and you're running it as root.

Answer 2

The overlay-scrollbar package does not come in i386 or amd64 flavors; it comes as an "all" flavor, which installs on all archs.

It appears to be missing the Multi-Arch: allowed header so it won't satisfy an i386 package depending on it. You should file a bug report asking that the missing header be added.