$ git clone -n https://src.fedoraproject.org/rpms/rubygem-sequel.git /var/lib/mock/f45-build-35283-694/root/chroot_tmpdir/scmroot/rubygem-sequel
Cloning into '/var/lib/mock/f45-build-35283-694/root/chroot_tmpdir/scmroot/rubygem-sequel'...
$ git fetch origin c164c1e1b92519ca62b60d7383afa784659daaa1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-sequel
 * [new ref]         c164c1e1b92519ca62b60d7383afa784659daaa1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c164c1e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild