Downgrading packages on Manjaro ARM (on the example of boinc)

[wrzomar]

There is a problem with boincmgr from the newest boinc package (7.16.9), it's impossible to add projects.
The solutions are:
- wait for update,
- use another boincmgr over network,
- downgrade boinc package.
In Arch Linux there is a way to downgrade a package installing a package (from cache or from Arch Linux Archive a.k.a ALA) and blocking its version in /etc/pacman.conf using IgnorePkg definition.
You can do it manually or using 'downgrade' script from AUR. The catch (on Manjaro ARM) is the downgrade script uses default ALA url (https://archive.archlinux.org/) and unless you have older versions of boinc in your cache, it fails to downgrade boinc package.
ARM packages are archived here: http://tardis.tiny-vps.com/aarm/
To downgrade boinc manually you have to:
1. Go to '/aarm/packages/b/boinc/' http://tardis.tiny-vps.com/aarm/packages/b/boinc/
2. Download tar.xz and tar.xz.sig files with older version of boinc (e.g. 7.16.7)
http://tardis.tiny-vps.com/aarm/packages...pkg.tar.xz
http://tardis.tiny-vps.com/aarm/packages...tar.xz.sig
3. Verify package with 'pacman-key --verify'

Code:

pacman-key --verify boinc-7.16.7-1-aarch64.pkg.tar.xz.sig

4. If it's verified, install with:

Code:

sudo pacman -U boinc-7.16.7-1-aarch64.pkg.tar.xz

5. Block boinc from updating:
Add

Code:

IgnorePkg = boinc

line to the /etc/pacman.conf and synchronize (you will have to close update icon before, I had to reboot for pamac-manager to block boinc updates):

Code:

sudo pacman -Syyu

The easier way is by downgrade script, you need to install it from AUR with pamac-manager or manually:
First install yay:

Code:

sudo pacman -Sy yay

Then install downgrade:

Code:

yay -S downgrade

Then you will need to "tell" downgrade script ALA url using its cli option:

Code:

downgrade --ala-url http://tardis.tiny-vps.com/aarm/ boinc

or create bash alias and then use this alias to run downgrade:
Open ~/.bashrc with your favourite text editor and add line:

Code:

alias downgrade-arm='downgrade --ala-url http://tardis.tiny-vps.com/aarm/'

Then (in new shell) you can use this alias like regular downgrade:

Code:

downgrade-arm boinc

Then you will be asked couple of questions, to choose version and to add IgnorePkg (the last one is only if package was not ignored already).
Downgrading packages in Manjaro is better explained here:
https://wiki.manjaro.org/index.php?title...g_packages