Prevent flatpaks from being installed

[Forpli]

Can you please tell me if locking the flatpak version has worked because flatpak was set at recommends but not depends?

I'd like to learn more about that and test in a live session what would happen if the thunderbird package had flatpak at depends.

I read here how to change the dependencies of a .deb package. I'm not sure if the guide still works and works in Zorin/Ubuntu. Maybe I have to change the paths.

Debian (.deb) Pakete bearbeiten: Abhängigkeiten anpassen

Then I could remove the line Recommends: flatpak and add a line Depends: flatpak and save the file with another name.
Unfortunately there is not shown what to do then.

I think I shouldn't install Thunderbird the usual way; instead, I should first just download it without installing it, then edit and save it, and finally install the modified version from that directory.

Edit: My test was successful, the guide worked in Zorin without adapting paths.
I downloaded thunderbird

apt download thunderbird

then ran

dpkg-deb --extract ~/thunderbird_2%3a1zorin3flathub_all.deb tmp

dpkg --control ~/thunderbird_2%3a1zorin3flathub_all.deb tmp/DEBIAN

Opened the file control at ~/tmp/DEBIAN/control
and changed the word Recommends to Depends (also added my name to the Maintainer and added .mod at the end of the version, but that is not necessary) and saved the file.
After that I built a new .deb package with an adapted name

dpkg --build tmp thunderbird_2%3a1zorin3mod_flathub_all.deb

I have removed flatpak and flatpak-plugin before, created a .pref file for apt preferences and locked flatpak with

sudo apt-mark hold flatpak

Then I doubleclicked on the new modified .deb file in ~ to install the package with gnome-software.

It was shown that the installation of thunderbird is not possible:
The following packages have unmet dependencies:
thunderbird
Depends on: flatpak but is not going to be installed

The screenshot shows the downloaded thunderbird .deb file and the new built modified .deb file and the modified control file

So it seems that the result is independent of whether flatpak was set as recommended or required dependency. But I'm not sure. That is uncharted territory to me. I also tested it with Pre-Depends instead of Depends, and got the same result there.

[Forpli]

I'm not sure if it is a good idea to lock the flatpak package. The "apt-cache rdepends flatpak" command shows zorin-os-desktop depending on it.
It breaks the package manager when flatpak can´t be installed. I had to run "sudo apt --fix-broken install" to repair my package manager after the tests.

[Aravisian]

apt-cache rdepends flatpak                                                                     
flatpak
Reverse Depends:
  zorin-windows-app-support
  zorin-os-lite-desktop-minimal
  zorin-os-lite-desktop
  zorin-os-desktop
  thunderbird
  podman-toolbox
  ostree-push

Fascinating. On Zorin OS, WINE depends on Flatpak, now?

I never did install the latest Zorin Lite Desktop after it was released. I had stuck with my own build.
The reason I had not was due to the ZorinGroups rather strong push for CSD's.

I am glad now that I never got around to it.

[Ponce-De-Leon]

@Aravisian

Fascinating. On Zorin OS, WINE depends on Flatpak, now?

The Windows App Support installs Bottles, too - which is a Flatpak. Maybe that is the Reason for the Dependency.

[wsmather]

How can I get that "malcontent gui?" Sounds interesting.

[swarfendor437]

Malcontent is in your menu but is known as Parent Control.

[Forpli]

Would the lock of flatpak lead to problems as it is a dependency of the desktop, e.g. when you want to run the "sudo apt reinstall zorin-os-desktop" command or there is an update for the zorin os desktop package?
Would it break the package manager each time (maybe because of a incomplete installed package) or show an error that the package couldn't be installed?

If I changed the dependencies of the zorin-os-desktop package manually and remove flatpak and the flatpak plugin from the control file, would it be overwritten by an update of the zorin-os-desktop package?

[Forpli]

I looked into it more closely. Flatpak and the gnome-software-flatpak-plugin are only recommended dependencies for the Zorin Desktop (and also zorin-windows-app-support), not mandatory ones.
Therefore, they would not be reinstalled if you reinstall the desktop. This means that as long as the developers do not designate them as mandatory for the Zorin Desktop package, locking flatpak should not cause any harm, or?