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

Solution 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.

Solution 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.