$ git clone -n https://src.fedoraproject.org/rpms/fluxbox.git /var/lib/mock/f45-build-9122-399/root/chroot_tmpdir/scmroot/fluxbox
Cloning into '/var/lib/mock/f45-build-9122-399/root/chroot_tmpdir/scmroot/fluxbox'...
$ git fetch origin 8dd7a1acf28465e7fbaddb32bae3383bdd59a165:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fluxbox
 * [new ref]         8dd7a1acf28465e7fbaddb32bae3383bdd59a165 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8dd7a1a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild