Added a comment for cuCascade issue #147

Author: yayen-lin

src/include/cudf/list_offset_fixup.hpp

@@ -32,6 +32,9 @@ namespace sirius {
  * columns use INT32 (cudf::size_type) offsets. A LIST whose offsets child is INT64 is misread
  * by every list algorithm, collapsing the sublists.
  *
+ * Workaround for the upstream cuCascade bug NVIDIA/cuCascade#147; remove this once the LIST
+ * offsets are no longer promoted to INT64 during reconstruction.
+ *
  * This is the single, central place where that promotion is reversed: it walks the GPU table
  * held by @p batch and rebuilds each LIST column (recursing into nested lists) with INT32
  * offsets, moving the values child and null mask (no payload copy) and reallocating only the