$ git clone -n https://src.fedoraproject.org/rpms/rubygem-curb.git /var/lib/mock/f45-build-34914-692/root/chroot_tmpdir/scmroot/rubygem-curb
Cloning into '/var/lib/mock/f45-build-34914-692/root/chroot_tmpdir/scmroot/rubygem-curb'...
$ git fetch origin ff553b152f535fcce6450497646c71716761dc04:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-curb
 * [new ref]         ff553b152f535fcce6450497646c71716761dc04 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ff553b1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild