$ git clone -n https://src.fedoraproject.org/rpms/toolbox.git /var/lib/mock/f40-build-2235240-53420/root/chroot_tmpdir/scmroot/toolbox
Cloning into '/var/lib/mock/f40-build-2235240-53420/root/chroot_tmpdir/scmroot/toolbox'...
$ git fetch origin 25a9050dd041d0425c78c3c71476d0fdf8c16c21:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/toolbox
 * [new ref]         25a9050dd041d0425c78c3c71476d0fdf8c16c21 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 25a9050 Remove deprecated %patchN syntax