On my AMD64 machine, with a current "apt-get update" of the oneiric archive, I'm seeing the following behavior:
$ sudo apt-get install libglib2.0-0:i386
... irrelevant things elided...
The following packages will be REMOVED:
accountsservice acpi-support acpid aisleriot akonadi-backend-mysql
... almost every package on the system
zeitgeist-datahub zeitgeist-extension-fts zenity
The following NEW packages will be installed:
gcc-4.6-base:i386 klogd libc6:i386 libffi6:i386 libgcc1:i386
libglib2.0-0:i386 libpcre3:i386 libselinux1:i386 pinentry-curses sysklogd
zlib1g:i386
The following packages will be upgraded:
kde-baseapps-data libgpgme++2
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
e2fsprogs util-linux (due to e2fsprogs) hostname upstart (due to hostname)
2 upgraded, 11 newly installed, 1109 to remove and 3 not upgraded.
Need to get 5,878 kB of archives.
After this operation, 2,542 MB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase 'Yes, do as I say!'
The underlying problem is that the i386 and amd64 archives are out of sync at present in the archive and have different versions of libglib2.0-0. Observe:
$ sudo apt-get install libglib2.0-0:i386 libglib2.0-0
Reading package lists... Done
Building dependency tree
Reading state information... Done
libglib2.0-0 is already the newest version.
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:
libglib2.0-0 : Breaks: libglib2.0-0:i386 (!= 2.29.18-0ubuntu3) but 2.29.90-0ubuntu1 is to be installed
libglib2.0-0:i386 : Breaks: libglib2.0-0 (!= 2.29.90-0ubuntu1) but 2.29.18-0ubuntu3 is to be installed
E: Unable to correct problems, you have held broken packages.
The particular problem with glib here is transient; it will go away whenever an up to date AMD64 package makes it into the archive. however, in response to the first command, perhaps apt should warn that the two packages are out of sync rather than trying to remove everything in sight?
ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: apt 0.8.16~exp5ubuntu6
ProcVersionSignature: Ubuntu 3.0.0-10.16-generic 3.0.4
Uname: Linux 3.0.0-10-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Wed Sep 7 13:01:58 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
LANGUAGE=en_US:en
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: apt
UpgradeStatus: No upgrade log present (probably fresh install)
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