Added mwe

test/mwe_bug.jl

@@ -0,0 +1,36 @@
+using P4est_wrapper
+using GridapP4est
+using Gridap
+using PartitionedArrays
+
+np = 1
+ranks = with_mpi() do distribute
+  distribute(LinearIndices((np,)))
+end
+
+Dc = 3
+domain = (Dc==2) ? (0,1,0,1) : (0,1,0,1,0,1)
+nc     = (Dc==2) ? (2,2) : (2,2,2)
+
+nrefs  = 1
+cmodel = CartesianDiscreteModel(domain,nc)
+model  = UniformlyRefinedForestOfOctreesDiscreteModel(ranks,cmodel,nrefs) # Breaks
+
+############################################################################################
+# Going low-level on UniformlyRefinedForestOfOctreesDiscreteModel() constructor
+
+import GridapP4est: setup_ptr_pXest_objects
+
+comm = ranks.comm
+ptr_pXest_connectivity,ptr_pXest,ptr_pXest_ghost,ptr_pXest_lnodes = setup_ptr_pXest_objects(Val{Dc},
+                                                                                            comm,
+                                                                                            cmodel,
+                                                                                            nrefs)
+
+pXest = ptr_pXest[]
+p8est_tree_array_index(pXest.trees, 0)[] # Fails
+
+Int(pXest.trees[].elem_size) # 216
+sizeof(p8est_tree_t) # 168
+sizeof(p4est_tree_t) # 216
+# So it seems we have a p4est_tree_t instead?