$ git clone -n https://src.fedoraproject.org/rpms/sexpp.git /var/lib/mock/f41-build-829031-155952/root/chroot_tmpdir/scmroot/sexpp
Cloning into '/var/lib/mock/f41-build-829031-155952/root/chroot_tmpdir/scmroot/sexpp'...
$ git fetch origin 445ec29b035ee7a38af9f387074ccc6ff7ce766e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/sexpp
 * [new ref]         445ec29b035ee7a38af9f387074ccc6ff7ce766e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 445ec29 Disable i686 build