$ git clone -n https://github.com/xcp-ng-rpms/qemu /var/lib/mock/v8.3-u-tae1-9147-27960/root/chroot_tmpdir/scmroot/qemu
Cloning into '/var/lib/mock/v8.3-u-tae1-9147-27960/root/chroot_tmpdir/scmroot/qemu'...
$ git fetch origin 02b7852aacd83ededb34a4b1ef99fb39b1189a6e:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/qemu
 * [new ref]         02b7852aacd83ededb34a4b1ef99fb39b1189a6e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 02b7852 bump release for test build