I found the patch that breaks Screamer sound support for qemu-system-ppc. It is this:
commit 2ceb8240fa4e4e30fb853565eb2bed3032d74f62 Author: Kővágó, Zoltán <dirty.ice...@gmail.com> Date: Thu Sep 19 23:24:11 2019 +0200 coreaudio: port to the new audio backend api Signed-off-by: Kővágó, Zoltán <dirty.ice...@gmail.com> Message-id: 586a1e66de5cbc6c5234f9ae556d24befb6afada.1568927990.git.dirty.ice...@gmail.com Signed-off-by: Gerd Hoffmann <kra...@redhat.com> Reversing this patch should make the Screamer patch work with the current git version of QEMU.