$ git clone -n https://src.fedoraproject.org/rpms/BlockOutII.git /var/lib/mock/f45-build-39808-759/root/chroot_tmpdir/scmroot/BlockOutII
Cloning into '/var/lib/mock/f45-build-39808-759/root/chroot_tmpdir/scmroot/BlockOutII'...
$ git fetch origin 1b2660ccc46faef6084f874230442ffb7f1b30a7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/BlockOutII
 * [new ref]         1b2660ccc46faef6084f874230442ffb7f1b30a7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1b2660c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild