$ git clone -n https://src.fedoraproject.org/rpms/R-jsonlite.git /var/lib/mock/f45-build-6223-347/root/chroot_tmpdir/scmroot/R-jsonlite
Cloning into '/var/lib/mock/f45-build-6223-347/root/chroot_tmpdir/scmroot/R-jsonlite'...
$ git fetch origin 92f7a9cb8f7bd36c3346b08ad529a7117ee96182:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-jsonlite
 * [new ref]         92f7a9cb8f7bd36c3346b08ad529a7117ee96182 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 92f7a9c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild