# Downgrading packages

Related articles

- Arch Build System
- makepkg
- pacman
- Arch Linux Archive

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Reason: soname bumps, cf. Frequently_asked_questions#What_if_I_run_a_full_system_upgrade_and_there_will_be_an_update_for_a_shared_library.2C_but_not_for_the_apps_that_depend_on_it.3F (Discuss in Talk:Downgrading packages#)

Before downgrading a single or multiple packages, consider why you wish to do so. If it is due to a bug, search the bug tracker for existing tasks. If there is none, add a new task; it is better to correct bugs, or at least warn other users of possible issues.

Warning:

- Downgrading one package may require that its dependencies be downgraded as well. When the number of packages to downgrade is large, consider using a snapshot. See Arch Linux Archive#How to restore all packages to a specific date.
- Be careful with changes to configuration files and scripts. For now pacman will handle this for us, as long as we do not bypass its safeguards.

## Return to an earlier package version

### Using the pacman cache

If a package was installed at an earlier stage, and the pacman cache was not cleaned, install an earlier version from `/var/cache/pacman/pkg/`.

This process will remove the current package and install the older version. Dependency changes will be handled, but pacman will not handle version conflicts. If a library or other package needs to be downgraded with the packages, please be aware that you will have to downgrade this package yourself as well.

    # cd /var/cache/pacman/pkg/
    # pacman -U <file_name_of_the_package>

Once the package is reverted, temporarily add it to the IgnorePkg section of `pacman.conf`, until the difficulty with the updated package is resolved.

### Downgrading the kernel

If you are unable to boot after a kernel update, then you can downgrade the kernel via a live CD. Use a fairly recent Arch Linux installation medium. Once it has booted, mount the partition where your system is installed to `/mnt`, and if you have `/boot` or `/var` on separate partitions, mount them there as well (e.g. `mount /dev/sdc3 /mnt/boot`). Then chroot into the system:

    # arch-chroot /mnt /bin/bash

Here you can go to `/var/cache/pacman/pkg` and downgrade the packages. At least downgrade linux, linux-headers and any kernel modules. For example:

    # pacman -U linux-3.5.6-1-x86_64.pkg.tar.xz linux-headers-3.5.6-1-x86_64.pkg.tar.xz virtualbox-host-modules-4.2.0-5-x86_64.pkg.tar.xz

Exit the chroot (with `exit`), reboot and you should be done.

### Arch Linux Archive

The Arch Linux Archive is a daily snapshot of the official repositories.

The ALA can be used to install a previous package version, or restore the system to an earlier date.

### Rebuild the package

If the package is unavailable, find the correct PKGBUILD and rebuild it with makepkg.

For packages from the official repositories, retrieve the PKGBUILD with ABS and change the software version. Alternatively, find the package on the Packages website, click "View Changes", and navigate to the desired version. The files are available through a `.tar.gz` snapshot, and via the Tree view.

See also Getting PKGBUILDs from SVN#Checkout an older revision of a package.

Old AUR packages can be obtained from aur-mirror. See Arch User Repository#Git repositories for AUR3 packages for details.

#### vABS - Versioned Arch Build System

vABS is an addition to ABS that has as main goal to keep different versions of the official PKGBUILDs. In ABS you have the latest versions of PKGBUILDs, while in vABS you also have old versions (up to 2 years). Select the desired version and download the build files tgz package or individual files and easily build your package with pkgbuild. More information about the service can be found here.

### Automation

downgraderAUR is a tool which works with libalpm, supports the pacman log and downgrading packages using Arch Linux Archive, local cache and ARM.

The downgradeAUR package is a Bash script to downgrade one (or multiple) packages, by using the pacman cache or the Arch Rollback Machine. See `man downgrade` for details.

agetpkg-gitAUR quickly lists/gets/installs packages from the Arch Linux Archive.

## Return from [testing]

See Official repositories#Disabling testing repositories.

Category:

- Package management

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