Build an Anylinux AppImage in Flatpak runtime?

[mcarans]

I was wondering if anyone has tried to build an Anylinux AppImage using Flatpak builder and a Flatpak runtime. The reason I thought of this is we already build a Flatpak using the latest runtime. If it were possible to make another build (or use the existing build) to get the executable and all dependencies required for an AnyLinux AppImage, we would have a Flatpak and an AppImage using exactly the same library versions, unlike our current AppImage which was built on Ubuntu 22.

AI suggests that "to achieve this, you would follow a "Harvesting" approach:

1. Enter the Flatpak SDK. Use the Flatpak SDK as your build shell. flatpak run --devel --command=sh org.freedesktop.Sdk//25.08
2. Compile/Install your app. Build your application inside this shell. It will link against the libraries in the Flatpak runtime (located at /usr/lib).
3. Run quick-sharun. Inside the Flatpak shell, run the quick-sharun script pointing to your compiled binary. sharun will use strace to find every library the app touches in the Flatpak runtime. It will copy those libraries, the linker, and the libc into a new AppDir.
4. Create the AppImage. Once sharun has bundled the environment, you use the --make-appimage flag."

Is this feasible?

[Samueru-sama]

I don't recommend doing this because:

• You should really use our debloated packages, otherwise any appimage you make will over 2x bigger than needed.

• flatpak apps are often hardcoded to write to /app and /var.

You can try exporting a .flatpak file and packaging that, I have done that already and it was painful as well

What application are you trying to package? For python apps sharun has built in python uv integration which makes it super quick to build them.

[mcarans]

@Samueru-sama This is what I would like to package: https://oolite.space/ (Code here: https://github.com/OoliteProject/oolite).

[mcarans]

@Samueru-sama Absolutely. That would be great! 1.92-maintenance branch has the current stable release 1.92.1, but if easier go ahead with the Arch package which is slightly older I think.

[Samueru-sama]

@Samueru-sama Absolutely. That would be great! 1.92-maintenance branch has the current stable release 1.92.1, but if easier go ahead with the Arch package which is slightly older I think.

https://github.com/pkgforge-dev/oolite-appimage-demo/releases

[mcarans]

Wow, so fast! I tested and it works fine on my Kubuntu 25.10 machine. I'll ask others to test.

[Samueru-sama]

I was not able to build it for aarch64 due to some endianess issue btw

which is a shame, because @Link4Electronics has an smartphone with postmarketOS (musl) and tests our appimages there.

[mcarans]

Yes unfortunately it does not work on aarch64 at the moment. The game was originally developed on Mac in Objective-C around 2006. It was ported to Windows and Linux. Then it stop working on Mac when it changed architecture in 2019. The hope is one day to get it working on Mac again and also aarch64 Windows and Linux.

I only started working on it mid last year when it didn't work on Linux and was using very old gcc on Windows and I updated many of the dependencies. Another dev released it on the Windows store and I released it on FlatHub. An AnyLinux AppImage will be really good for any AppImage portals.

[Samueru-sama]

cc @Link4Electronics this might interest you.

[Link4Electronics]

Interesting indeed, one more game that looks like works on powerpc linux if compile, we have 202 members and counting of powerpc enthusiasts at archpower linux discord server lol
Than there's wii/wiiu-linux discord server with 315 members, MorphOS discord sv 388 members and free060 125 members for xbox360 linux