Chapter 1. Introduction

Table of Contents

1.1. Reporting bugs on this document
1.2. Contributing upgrade reports
1.3. Sources for this document

This document informs users of the Debian distribution about major changes in version 11 (codenamed bullseye).

The release notes provide information on how to upgrade safely from release 10 (codenamed buster) to the current release and inform users of known potential issues they could encounter in that process.

You can get the most recent version of this document from


Note that it is impossible to list every known issue and that therefore a selection has been made based on a combination of the expected prevalence and impact of issues.

Please note that we only support and document upgrading from the previous release of Debian (in this case, the upgrade from buster). If you need to upgrade from older releases, we suggest you read previous editions of the release notes and upgrade to buster first.

1.1. Reporting bugs on this document

We have attempted to test all the different upgrade steps described in this document and to anticipate all the possible issues our users might encounter.

Nevertheless, if you think you have found a bug (incorrect information or information that is missing) in this documentation, please file a bug in the bug tracking system against the release-notes package. You might first want to review the existing bug reports in case the issue you've found has already been reported. Feel free to add additional information to existing bug reports if you can contribute content for this document.

We appreciate, and encourage, reports providing patches to the document's sources. You will find more information describing how to obtain the sources of this document in Section 1.3, “Sources for this document”.

1.2. Contributing upgrade reports

We welcome any information from users related to upgrades from buster to bullseye. If you are willing to share information please file a bug in the bug tracking system against the upgrade-reports package with your results. We request that you compress any attachments that are included (using gzip).

Please include the following information when submitting your upgrade report:

  • The status of your package database before and after the upgrade: dpkg's status database available at /var/lib/dpkg/status and apt's package state information, available at /var/lib/apt/extended_states. You should have made a backup before the upgrade as described at Section 4.1.1, “Back up any data or configuration information”, but you can also find backups of /var/lib/dpkg/status in /var/backups.

  • Session logs created using script, as described in Section 4.4.1, “Recording the session”.

  • Your apt logs, available at /var/log/apt/term.log, or your aptitude logs, available at /var/log/aptitude.


You should take some time to review and remove any sensitive and/or confidential information from the logs before including them in a bug report as the information will be published in a public database.

1.3. Sources for this document

The source of this document is in DocBook XML format. The HTML version is generated using docbook-xsl and xsltproc. The PDF version is generated using dblatex or xmlroff. Sources for the Release Notes are available in the Git repository of the Debian Documentation Project. You can use the web interface to access its files individually through the web and see their changes. For more information on how to access Git please consult the Debian Documentation Project VCS information pages.