Comment 8 for bug 1921664

> Maybe it depends on what arm platform (as there are often subtle differences) or which storage (as > the assert is about storage) you run on.
> My CPU is an X-Gene and my Storage is a ZFS (that backs my container running hirsute and Hirsute's > qemu).
> What is it for you?

Sorry, I thought I had already reported that, but it's not clear. My setup is special in a couple of ways:
- I'm running Ubuntu/Arm64 (21.04 beta, fully up-to-date except kernel), but ...
- it's a virtual machine on a macOS/Mac Mini M1 (fully up-to-date)
- It's running the 5.8.0-36-generic which isn't the latest (for complicated reasons)

I'll try to bring my Raspberry Pi 4 back up on Ubuntu and see if I can reproduce it there.

> Is this failing 100% of the times for you, or just sometimes and maybe racy?

100% consistently reproducible with the official packages. 0% reproducible with my own build

> A hint which versions to look at can be derived from
> $ grep -- qemu-system-misc /var/log/dpkg.log

Alas, I had critical space issues and /var/log was among the casualties

> Could you rebuild what you get with "apt source qemu". That will be 5.2 plus the Delta we have...

TIL. I tried `apt source --compile qemu` but it complains

  dpkg-checkbuilddeps: error: Unmet build dependencies: gcc-alpha-linux-gnu gcc-powerpc64-linux-gnu

but these packages are not available [anymore?]. I don't currently have the time to figure this out.

> FYI my qemu is still busy

It's hung. The boot take ~ 20 seconds on my host. Multi-minutes is not normal.

If I can reproduce this on a Raspberry Pi 4, then I'll proceed with your suggestions above, otherwise I'll pause this until I can run Ubuntu natively on the Mac Mini.