$ git clone -n https://github.com/xcp-ng-rpms/qemu.git /var/lib/mock/v8.3-incoming-9687-28409/root/chroot_tmpdir/scmroot/qemu
Cloning into '/var/lib/mock/v8.3-incoming-9687-28409/root/chroot_tmpdir/scmroot/qemu'...
$ git fetch origin 39fd36a6dbbb9d686dd5b6a911b376fd627a98fa:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/qemu
 * [new ref]         39fd36a6dbbb9d686dd5b6a911b376fd627a98fa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 39fd36a Merge pull request #9 from xcp-ng-rpms/8.3-rebase-XS-4.2.1-5.2.14