Debugger not found in iex -S mix

With code path pruning in Elixir v1.15, any application not listed in your mix.exs is not available.

You can invoke this before:

iex> Mix.ensure_application!(:wx)
iex> Mix.ensure_application!(:debugger)

and then you should be able to start it. The :wx line won’t be necessary from Erlang/OTP 27+.