$ git clone -n https://src.fedoraproject.org/rpms/dogtag-pki.git /var/lib/mock/f42-build-3436153-45433/root/chroot_tmpdir/scmroot/dogtag-pki
Cloning into '/var/lib/mock/f42-build-3436153-45433/root/chroot_tmpdir/scmroot/dogtag-pki'...
$ git fetch origin 3870a2599f20eba7e96fc95089e9e514c723d241:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dogtag-pki
 * [new ref]         3870a2599f20eba7e96fc95089e9e514c723d241 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3870a25 Add sysusers.d config file to allow rpm to create users/groups automatically