$ git clone -n https://github.com/xcp-ng-rpms/amd-microcode.git /var/lib/mock/v8.3-incoming-9807-28521/root/chroot_tmpdir/scmroot/amd-microcode
Cloning into '/var/lib/mock/v8.3-incoming-9807-28521/root/chroot_tmpdir/scmroot/amd-microcode'...
$ git fetch origin ff6efe13e89a51c2dec55beb7e6119a58b772890:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/amd-microcode
 * [new ref]         ff6efe13e89a51c2dec55beb7e6119a58b772890 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ff6efe1 Update AMD microcodes to the 2025-12-03 drop