the package libtbb2 can't be installed in 64 bit and 32 bit at the same time

[hen]

the package libtbb2 (64 bit) is installed on my system because some other packages depend on it (e.g. blender). I try to install the 32 bit version of libtbb2:
apt-get install libtbb2:i386

but this installation would uninstall libtbb2 (64 bit) and all packages that depend on it (e.g. blender). So 32-bit Software that requires libtbb2 (32-bit) can't be used or all packages that depend on libtbb2 (64 bit) have to be uninstalled. This behaviour isn't correct.

This happens on ubuntu 15.10 and on 14.04 too.

way to reproduce:
apt-get install libtbb2 libtbb2:i386

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: dpkg 1.18.2ubuntu5.1
ProcVersionSignature: Ubuntu 4.2.0-19.23-generic 4.2.6
Uname: Linux 4.2.0-19-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CurrentDesktop: KDE
Date: Thu Dec 17 18:37:47 2015
InstallationDate: Installed on 2015-12-13 (3 days ago)
InstallationMedia: Kubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
SourcePackage: dpkg
UpgradeStatus: No upgrade log present (probably fresh install)

[Adam Conrad (adconrad)]

tbb was multiarched in Xenial (16.04)