We prune:

https://github.com/elixir-lang/elixir/blob/master/lib/elixir/lib/kernel/cli.ex#L103-L117
https://github.com/elixir-lang/elixir/blob/master/lib/ex_unit/lib/ex_unit/runner.ex#L271-L279
https://github.com/elixir-lang/elixir/blob/master/lib/elixir/src/elixir_dispatch.erl#L276-L288

The last one concerns macros.