$ git clone -n https://github.com/xcp-ng-rpms/blktap.git /var/lib/mock/v8.3-incoming-11475-29780/root/chroot_tmpdir/scmroot/blktap
Cloning into '/var/lib/mock/v8.3-incoming-11475-29780/root/chroot_tmpdir/scmroot/blktap'...
$ git fetch origin de810df8f048f3fe68d86bf5d6d46a813bb1ffc1:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/blktap
 * [new ref]         de810df8f048f3fe68d86bf5d6d46a813bb1ffc1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at de810df Add QCOW2 support