$ git clone -n https://src.fedoraproject.org/rpms/g2clib.git /var/lib/mock/f40-build-2226516-52939/root/chroot_tmpdir/scmroot/g2clib
Cloning into '/var/lib/mock/f40-build-2226516-52939/root/chroot_tmpdir/scmroot/g2clib'...
$ git fetch origin 35ce2d0bdaa32e1dee0da065370a256d815ea62a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/g2clib
 * [new ref]         35ce2d0bdaa32e1dee0da065370a256d815ea62a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 35ce2d0 rebuild after so name jump of libjasper