$ git clone -n https://src.fedoraproject.org/rpms/R-sourcetools.git /var/lib/mock/f45-build-6435-348/root/chroot_tmpdir/scmroot/R-sourcetools
Cloning into '/var/lib/mock/f45-build-6435-348/root/chroot_tmpdir/scmroot/R-sourcetools'...
$ git fetch origin c16df3e24242dcacc5bb9911fa01b5717e1a2c2b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-sourcetools
 * [new ref]         c16df3e24242dcacc5bb9911fa01b5717e1a2c2b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c16df3e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild