Fix concat form comparison

src/dask_awkward/lib/operations.py

@@ -7,7 +7,6 @@
 from awkward.operations.ak_concatenate import (
     enforce_concatenated_form as enforce_layout_to_concatenated_form,
 )
-from awkward.typetracer import typetracer_from_form
 from dask.base import tokenize
 from dask.highlevelgraph import HighLevelGraph
 
@@ -65,29 +64,18 @@ def concatenate(
     if len(metas) == 0:
         raise ValueError("Need at least one array to concatenate")
 
-    # Are we performing a _logical_ concatenation?
     if axis == 0:
         # There are two possible cases here:
         # 1. all arrays have identical metas — just grow the Dask collection
         # 2. some arrays have different metas — coerce arrays to same form
-
-        # Drop reports from metas to avoid later touching any buffers
-        metas_no_report = [
-            typetracer_from_form(x.layout.form, behavior=x.behavior, attrs=x._attrs)
-            for x in metas
-        ]
-        # Concatenate metas to determine result form
-        meta_no_report = ak.concatenate(
-            metas_no_report, axis=0, behavior=behavior, attrs=attrs
-        )
-        intended_form = meta_no_report.layout.form
+        intended_form = metas[0].layout.form
 
         # If any forms aren't equal to this form, we must enforce each form to the same type
         if any(
             not m.layout.form.is_equal_to(
                 intended_form, all_parameters=True, form_key=False
             )
-            for m in metas_no_report[1:]
+            for m in metas[1:]
         ):
             arrays = [
                 map_partitions(
@@ -122,13 +110,14 @@ def concatenate(
 
             aml = AwkwardMaterializedLayer(g, previous_layer_names=[arrays[0].name])
 
+        new_meta = ak.copy(metas[0])
+        new_meta._report = report
         hlg = HighLevelGraph.from_collections(name, aml, dependencies=arrays)
-        meta_no_report._report = report
-        aml.meta = meta_no_report
+        aml.meta = new_meta
         return new_array_object(
             hlg,
             name,
-            meta=meta_no_report,
+            meta=new_meta,
             npartitions=sum(a.npartitions for a in arrays),
         )