Linux

We could take this further and let developers specify exactly the dependencies they need! No more bloated runtimes! App A could specify libfoo>=1.23.45 while app B specify libfoo<1.24 and Flatpak could resolve the compatible version automatically!

Serious answer: If space saving is the goal, traditional packaging is the way to go. Allowing multiple runtimes is a slippery slope away from the core idea of Flatpak (simplest dependency management possible so developers don’t have to test many configurations).

(Not that there’s anything wrong with traditional packaging with more complicated dependency management - it’s just not Flatpak’s thing).

Good Idea in theory, but i think it would fall short because

• supporting multiple runtimes requires more develeoper effort, if even possible
• a single app is enough for a runtime to be required to be present. So it's unlikely to save space
• The number of possible runtimes isn't that high anyway. I think the flatpak folder on my pc is like 10GiB.

To answer the question of “why not” we only have to ask “what problem are Flatpaks meant to solve”:

• Flatpaks allow applications to run identically on different distributions
• Flatpaks reduce the burden for software providers having to support multiple environments

The way that Flatpaks achieve these goals is precisely by mandating the environment that the application will execute within.

Allowing the application to run in different environments goes directly against two core value propositions of the project.

Being resource efficient is not one of the primary goals of Flatpak. Providing a consistent and deterministic execution context is.

There is your answer.

I am sympathetic to the question and the desire though. This is one of the reasons I do not like Flatpaks. Dragging in these big environments, and the duplication of resources, feels very wasteful to me. I would like them even less though if they did not even deliver on their core promises.

Personally, I prefer Distrobox to Flatpak. At least I have more control. Arch / AUR in a distrobox will let you install pretty much any app on any distro. If the app you need only runs in one distro ( like Ubuntu ), you can create a Distrobox of that too.

What if there are breaking changes in a runtime between two versions?

And what sense would it make to define several different runtimes to begin with? Does your GTK application uses QT code and vice-versa? Or am I interpreting this wrong?

What do you need 45 for if it runs with 46? Update the app that's still on 45 instead of making sure yours runs with an outdated version.

Space is one of the least concerns for me on a computer, even if it is a phone. Besides, flatpak doesn't consume that much space anyway.