$ git clone -n https://src.fedoraproject.org/rpms/dist-git.git /var/lib/mock/f42-build-3528314-46309/root/chroot_tmpdir/scmroot/dist-git
Cloning into '/var/lib/mock/f42-build-3528314-46309/root/chroot_tmpdir/scmroot/dist-git'...
$ git fetch origin 337ca362b5b1113585a4f0fa21185e92ef2fcb0b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dist-git
 * [new ref]         337ca362b5b1113585a4f0fa21185e92ef2fcb0b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 337ca36 Add sysusers.d config file to allow rpm to create users/groups automatically