Using dynamics for ordering queries

[Svenito]

Environment

• Elixir version (elixir -v):
  Elixir 1.10.2 (compiled with Erlang/OTP 21)

• Database and version (PostgreSQL 9.4, MongoDB 3.2, etc.):
  PostgreSQL 12.2

• Ecto version (mix deps):
  3.3.4

• Database adapter and version (mix deps):
  ecto_sql 3.3.4

• Operating system:
  KDE Neon

The documentation at https://hexdocs.pm/ecto/dynamic-queries.html#building-dynamic-queries shows how to use dynamics for ordering results. I have tried this and while

dynamic([q], field(q, :id))

works, when trying to set the sort direction like this

dynamic([q], desc: field(q, :id))

results in the following error:

** (Ecto.Query.CompileError) Tuples can only be used in comparisons with literal tuples of the same size

I've asked this question on the Elixir forum and have a working solution, but it would seem that either the docs are inaccurate, or the feature mentioned isn't working as expected