$ git clone -n https://src.fedoraproject.org/rpms/R-bit.git /var/lib/mock/f45-build-5974-345/root/chroot_tmpdir/scmroot/R-bit
Cloning into '/var/lib/mock/f45-build-5974-345/root/chroot_tmpdir/scmroot/R-bit'...
$ git fetch origin 768c033da6a0a76ad899b5ce06283dbe864f912e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-bit
 * [new ref]         768c033da6a0a76ad899b5ce06283dbe864f912e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 768c033 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild