Fix julia 1.8 bug on tree deepcopy

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
       matrix:
         version:
           - '1.6'
-          - '1.7'
+          - '1.8'
           - 'nightly'
         os:
           - ubuntu-latest

src/entities/JunctionTreeTypes.jl

@@ -22,6 +22,37 @@ end
 
 const BayesTree = MetaBayesTree
 
+# NOTE Temporary fix? Overwrite deepcopy on MetaBayesTree to strip out copying the channels. 
+# see https://github.com/JuliaRobotics/IncrementalInference.jl/issues/1530
+# possible fix in https://github.com/JuliaLang/julia/pull/46406
+import Base.deepcopy_internal
+function Base.deepcopy_internal(bt::MetaBayesTree, stackdict::IdDict)
+
+  if haskey(stackdict, bt)
+      return stackdict[bt]
+  end
+
+  mg = bt.bt
+
+  graph = deepcopy_internal(mg.graph, stackdict)
+  vprops = deepcopy_internal(mg.vprops, stackdict)
+  T = eltype(mg)
+  # dropping all edge data
+  eprops = Dict{MetaGraphs.SimpleEdge{T},MetaGraphs.PropDict}()
+  gprops = deepcopy_internal(mg.gprops, stackdict)
+  weightfield = deepcopy_internal(mg.weightfield, stackdict)
+  defaultweight = deepcopy_internal(mg.defaultweight, stackdict)
+  metaindex = deepcopy_internal(mg.metaindex, stackdict)
+  indices = deepcopy_internal(mg.indices, stackdict)
+
+  mg_cpy = MetaDiGraph(graph, vprops, eprops, gprops, weightfield, defaultweight, metaindex, indices)
+
+  bt_cpy = MetaBayesTree(mg_cpy, bt.btid, deepcopy_internal(bt.frontals, stackdict), deepcopy_internal(bt.eliminationOrder, stackdict), bt.buildTime)
+
+  stackdict[bt] = bt_cpy
+  return bt_cpy
+end
+
 """
     $TYPEDEF