$ git clone -n https://src.fedoraproject.org/rpms/R-hexbin.git /var/lib/mock/f45-build-6275-347/root/chroot_tmpdir/scmroot/R-hexbin
Cloning into '/var/lib/mock/f45-build-6275-347/root/chroot_tmpdir/scmroot/R-hexbin'...
$ git fetch origin 1ff5f91ac40f9fc5be8a273329da90c612359deb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-hexbin
 * [new ref]         1ff5f91ac40f9fc5be8a273329da90c612359deb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1ff5f91 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild