$ git clone -n https://github.com/xcp-ng-rpms/blktap.git /var/lib/mock/v8.3-v-qcow2-9953-28633/root/chroot_tmpdir/scmroot/blktap
Cloning into '/var/lib/mock/v8.3-v-qcow2-9953-28633/root/chroot_tmpdir/scmroot/blktap'...
$ git fetch origin 6b6b18a8efdf6036b90f6459f849ecaed3305a69:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/blktap
 * [new ref]         6b6b18a8efdf6036b90f6459f849ecaed3305a69 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6b6b18a qcow2: fix eventfd delivery