$ git clone -n https://src.fedoraproject.org/rpms/device-mapper-persistent-data.git /var/lib/mock/f42-build-867428-175505/root/chroot_tmpdir/scmroot/device-mapper-persistent-data
Cloning into '/var/lib/mock/f42-build-867428-175505/root/chroot_tmpdir/scmroot/device-mapper-persistent-data'...
$ git fetch origin 42f0442c767c4c175e834002cb29f7489fd4fbb0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/device-mapper-persistent-data
 * [new ref]         42f0442c767c4c175e834002cb29f7489fd4fbb0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 42f0442 Rebuilt for the bin-sbin merge (2nd attempt)