$ git clone -n https://github.com/xcp-ng-rpms/qemu /var/lib/mock/v8.3-incoming-9141-27953/root/chroot_tmpdir/scmroot/qemu
Cloning into '/var/lib/mock/v8.3-incoming-9141-27953/root/chroot_tmpdir/scmroot/qemu'...
$ git fetch origin 3b912ca5a5fffc4f28f171f7876f8082c3d537cc:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/qemu
 * [new ref]         3b912ca5a5fffc4f28f171f7876f8082c3d537cc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3b912ca Add virtio-vga support