UnpackParticlesAndVertices has location problems

When running over HLT2 output and producing a tuple using FunTuple, UnpackParticlesAndVertices complains spamming UnpackParticlesAndVertices ERROR UnpackParticlesAndVertices:: Unpack('/Event/HLT2/pPhys/PP2MCPRelations'): missing destination '/Event/HLT2/MC/Particles', skip link StatusCode=FAILURE

fyi @gtuci

To reproduce run DaVinci/run davinci run-mc --inputfiledb Dst_D0pi-Kpi data.yaml --joboptfile opts.yaml --user_algorithms tuple:alg_config:

# opts.yaml
ntuple_file: root://eoslhcb.cern.ch//eos/lhcb/user/g/gunther/FunTupleTest/D0_Kpi_10evts.root
annsvc_config: root://eoslhcb.cern.ch//eos/lhcb/user/g/gunther/FunTupleTest/hlt2_10evts.tck.json 
unpack_stream: /Event

# data.yaml
Dst_D0pi-Kpi:
  filenames:
    - root://eoslhcb.cern.ch//eos/lhcb/user/g/gunther/FunTupleTest/hlt2_D0_Kpi_10evts.dst
  qualifiers:
    data_type: Upgrade
    input_type: ROOT
    simulation: true
    conddb_tag: sim-20210617-vc-md100
    dddb_tag: dddb-20210617

# tuple.py
from PyConf.application import make_data_with_FetchDataFromFile
from FunTuple import FunctorCollection
from FunTuple import FunTuple_Particles as Funtuple
import Functors as F

branches = {
    "D0": "[D0 -> K- pi+]CC",
    "Kminus": "[D0 -> ^K- pi+]CC",
    "piplus": "[D0 -> K- ^pi+]CC",
}

d0_variables = FunctorCollection({
    "PT": F.PT,
})
daughter_variables = FunctorCollection({
    "PT": F.PT,
})

variables = {
    "D0" : d0_variables,
    "Kminus" : daughter_variables,
    "piplus" : daughter_variables
}

my_tuple = Funtuple(
    name="Tuple",
    tree_name="DecayTree",
    branches=branches,
    variables=variables,
    inputs=make_data_with_FetchDataFromFile("/Event/HLT2/Hlt2CharmD0ToKmPipLine/Particles")
)

def alg_config():
    algs = [my_tuple]
    return {"UserAlgs": algs}, []

Links https://gitlab.cern.ch/lhcb-dpa/project/-/issues/121