This error occurs when a new Debian version is released, causing your system's release to transition from stable to oldstable. Use apt-get update --allow-releaseinfo-change to accept the change and continue updating packages.
When a new stable version of Debian is released (e.g., Debian 12 Bookworm), the previous stable release (e.g., Debian 11 Bullseye) automatically transitions to "oldstable" status. APT detects this change in the repository metadata and blocks updates as a safety measure to ensure you're aware of the release transition. The error indicates that your system's release information has been reclassified in the Debian repositories, and you need to explicitly acknowledge this change before continuing with package updates. This is a normal part of the Debian release cycle and is not indicative of corruption or malicious activity.
Execute the following command to explicitly accept the suite change and continue updating:
sudo apt-get update --allow-releaseinfo-changeThis command tells APT to proceed with the update despite detecting that the repository's Suite value has changed from stable to oldstable. Running this once resolves the error permanently for that repository.
Check that the command finishes without errors:
sudo apt-get update --allow-releaseinfo-changeYou should see output indicating package lists were successfully fetched. If there are still errors, they will be displayed at this point.
After the initial update with the flag, subsequent apt update commands will work normally without the flag:
sudo apt updateYou can now install or upgrade packages as usual. The suite change has been accepted by APT.
If you want to avoid needing the flag in the future (though not recommended unless you understand the implications), create an APT configuration file:
echo 'Acquire::AllowReleaseInfoChange::Suite "true";' | sudo tee /etc/apt/apt.conf.d/01allow_releaseinfo_changesThis allows APT to automatically accept suite changes without requiring the command-line flag. Only do this if you regularly maintain your system and are prepared for major Debian version transitions.
Understanding the Debian Release Cycle: Debian maintains a stable release for approximately 5 years. The timeline includes 3 years of full support followed by 2 years of Long Term Support (LTS). When a new stable version is released, the previous stable transitions to "oldstable" and continues receiving security updates for a limited period. If your sources.list references the suite name "stable" instead of a codename like "bookworm", your system will automatically track the newest stable release. To stick with a specific release, update your sources.list to use the codename instead: change "deb http://deb.debian.org/debian stable main" to "deb http://deb.debian.org/debian bookworm main". The --allow-releaseinfo-change flag has been available since APT 1.8.2 and exists specifically to prevent accidental breakage when repositories change critical metadata. Modern versions of apt (the newer interactive frontend) will prompt you interactively to accept the change, while apt-get requires the explicit flag.
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