$ git clone -n https://src.fedoraproject.org/rpms/rubygem-prawn-table.git /var/lib/mock/f45-build-35164-693/root/chroot_tmpdir/scmroot/rubygem-prawn-table
Cloning into '/var/lib/mock/f45-build-35164-693/root/chroot_tmpdir/scmroot/rubygem-prawn-table'...
$ git fetch origin dffca5cca0903c25f82d1e27046eba62b51a4e8e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-prawn-table
 * [new ref]         dffca5cca0903c25f82d1e27046eba62b51a4e8e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dffca5c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild