Comment 10 for bug 1906245

Fix works:
Preparing to unpack .../qemu-system-gui_1%3a5.1+dfsg-4ubuntu3_amd64.deb ...
cp: -r not specified; omitting directory '/var/run/qemu/Debian'
dpkg: warning: old qemu-system-gui:amd64 package pre-removal script subprocess returned error exit status 1
dpkg: trying script from the new package instead ...
dpkg: ... it looks like that went OK
Unpacking qemu-system-gui:amd64 (1:5.1+dfsg-4ubuntu3) over (1:5.1+dfsg-4ubuntu1) ...

Note:
if installing without proposed there is a block on
 qemu-system-gui : Depends: libgdk-pixbuf-2.0-0 (>= 2.22.0) but it is not installable
So to migrating this to hirsute-release this might have some dependencies.