I have a resource with an attribute that is an array of strings. Calculations on these arrays seem inconsistent:

  attribute :tags, {:array, :string}, allow_nil?: false

Some calculations:

  calculate :num_tags, :integer, expr(length(tags))
  calculate :all_tags, :string, expr(string_join(tags, ", "))
  calculate :reverse_tags, {:array, :string}, expr(lazy({__MODULE__, :reverse, [tags]}))

Loading :num_tags works, but loading :all_tags raises:
(Protocol.UndefinedError) protocol Enumerable not implemented for drivers of type Ash.Query.Ref (a struct)
If I substitute a literal list of strings the expression works.
When I include the third calculation it fails to compile, undefined variable “tags”, but if I wrap it to be [expr(tags)] then it compiled but I’m back to the Protocol.UndefinedError above, and yet it works with a literal list of strings.
It looks like some calculations on compound attributes don’t work. I’m using ash 2.21.12 and ash_postgres 1.5.23.