$ git clone -n https://src.fedoraproject.org/rpms/sexpp.git /var/lib/mock/f40-build-1466347-23686/root/chroot_tmpdir/scmroot/sexpp
Cloning into '/var/lib/mock/f40-build-1466347-23686/root/chroot_tmpdir/scmroot/sexpp'...
$ git fetch origin be2e344dd48687d1963d1d1ca702cb00d6bd5701:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/sexpp
 * [new ref]         be2e344dd48687d1963d1d1ca702cb00d6bd5701 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at be2e344 v0.8.8