Problem: Upgrade to UCS 5 fails with an dpkg: libc6:amd64 error

[mroessler]

Problem

While upgrading UCS to version 5 the process aborts and it shows an error like:

english:

• dpkg: libc6:amd64: dependency problems, but removing anyway as you requested:
• dpkg: error processing package libc6:amd64 (--remove):

german:

• dpkg: libc6:amd64: Abhängigkeitsprobleme, wird aber wie gefordert dennoch entfernt:
• dpkg: Fehler beim Bearbeiten des Paketes libc6:amd64 (--remove):

Solution

Please perform a backup before proceeding with the steps!

1. Search for i386 packages that are installed on UCS with:
   dpkg -l | grep i386 | grep -v amd64

The output is something like:

ii  gcc-6-base:i386                                     6.3.0-18+deb9u1                                                     i386         GCC, the GNU Compiler Collection (base package)
ii  gcc-8-base:i386                                     8.3.0-6~4.4.9.202204081402                                          i386         GCC, the GNU Compiler Collection (base package)
ii  libc6:i386                                          2.24-11+deb9u4                                                      i386         GNU C Library: Shared libraries
ii  libgcc1:i386                                        1:8.3.0-6~4.4.9.202204081402                                        i386         GCC support library
ii  libgpm2:i386                                        1.20.4-6.A~4.3.0.201711291434                                       i386         General Purpose Mouse - shared library
ii  libncurses5:i386                                    6.0+20161126-1+deb9u3                                               i386         shared libraries for terminal handling
ii  libstdc++6:i386                                     8.3.0-6~4.4.9.202204081402                                          i386         GNU Standard C++ Library v3
ii  libtinfo5:i386                                      6.0+20161126-1+deb9u3    

2. Uninstall the i386 architecture packages with the following command:
   apt remove <package>:i386

change <package> to the necessary package(s) from the output.

Repeat the process and check for survivor i386 packages with the first command from this section and then delete them until every i386 package is removed.

Root Cause

There are i386 packages installed via apt on an amd64 system architecture.

Investigation

1. Check the /var/log/univention/updater.log for the lines that are shown at the start of the article in the “Problem” section.
2. The system can not be started after a reboot.