$ git clone -n https://src.fedoraproject.org/rpms/rubygem-base32.git /var/lib/mock/f45-build-34798-691/root/chroot_tmpdir/scmroot/rubygem-base32
Cloning into '/var/lib/mock/f45-build-34798-691/root/chroot_tmpdir/scmroot/rubygem-base32'...
$ git fetch origin 423831f8e91da86225793558fcacc80f11094ea0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-base32
 * [new ref]         423831f8e91da86225793558fcacc80f11094ea0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 423831f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild