$ git clone -n https://src.fedoraproject.org/rpms/massif-visualizer.git /var/lib/mock/f42-build-side-1-3569474-46747/root/chroot_tmpdir/scmroot/massif-visualizer
Cloning into '/var/lib/mock/f42-build-side-1-3569474-46747/root/chroot_tmpdir/scmroot/massif-visualizer'...
$ git fetch origin b93d85d04c8361ccb6d784f2f73875dfc02fed6f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/massif-visualizer
 * [new ref]         b93d85d04c8361ccb6d784f2f73875dfc02fed6f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b93d85d 25.04.2