$ git clone -n https://src.fedoraproject.org/rpms/R-base64enc.git /var/lib/mock/f45-build-5982-345/root/chroot_tmpdir/scmroot/R-base64enc
Cloning into '/var/lib/mock/f45-build-5982-345/root/chroot_tmpdir/scmroot/R-base64enc'...
$ git fetch origin 78bfd6998474bf2ebf6fbab24c94461320f5afae:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-base64enc
 * [new ref]         78bfd6998474bf2ebf6fbab24c94461320f5afae -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 78bfd69 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild