$ git clone -n https://src.fedoraproject.org/rpms/gridsite.git /var/lib/mock/f45-build-13032-446/root/chroot_tmpdir/scmroot/gridsite
Cloning into '/var/lib/mock/f45-build-13032-446/root/chroot_tmpdir/scmroot/gridsite'...
$ git fetch origin 88bfdcdf04d9d656c14a42ca69c38bc5246dd0e7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gridsite
 * [new ref]         88bfdcdf04d9d656c14a42ca69c38bc5246dd0e7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 88bfdcd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild