Install qemu 9 from ubuntu oracular

[jannic]

No description provided.

[thejpster]

I see that this works in practice, but I don't know that it works in theory. Installing packages across Ubuntu revisions is generally frowned upon - you're supposed to use the backports process.

[jannic]

I'd fully agree if it was about installing some server that should run for a non-trivial amount of time. Supporting such a Frankenstein installation could become a nightmare, and it might also be difficult to downgrade it back to a pure 24.04 system.

But for a container that only lives for two minutes, and is only used for running some tests, I wouldn't be too concerned.

Of course, it's also fine to stay with the windows based approach. And for the same reasons: It's enough if it can run the tests, no need to administer the system. So it doesn't really matter if it is windows or linux.

So feel free to close this merge request. I mainly created it because I got nerd sniped by Adam's "it's easier to use windows in ci to run qemu 9 than to get qemu 9 for ubuntu" :-)

One small advantage of the ubuntu based approach: Even though the installation of qemu 9 with all its dependencies adds 662 MB to the container, it's still significantly faster than the windows approach. Like 1m22s vs 5m15s for the whole qemu-tests job. (Measurements from a single run each, I have no idea how much these values fluctuate.)

[jonathanpallant]

I compiled my own QEMU instead, which seemed safer. But thanks for the nudge!