$ git clone -n https://src.fedoraproject.org/rpms/oct2spec.git /var/lib/mock/f45-build-20836-574/root/chroot_tmpdir/scmroot/oct2spec
Cloning into '/var/lib/mock/f45-build-20836-574/root/chroot_tmpdir/scmroot/oct2spec'...
$ git fetch origin b86d676613f1a79eab6b2d2a5759624edd06fc08:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/oct2spec
 * [new ref]         b86d676613f1a79eab6b2d2a5759624edd06fc08 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b86d676 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild