Error when evaluating expression in debugger in Elixir 1.8.0

[michallepicki]

Describe the bug
Evaluating expression in debugger doesn't work with Elixir 1.8.0 or newer.
Elixir 1.8.0 and newer don't export :elixir.quoted_to_erl/3 anymore. Only :elixir.quoted_to_erl/2 is available.

To Reproduce
Steps to reproduce the behavior:

1. Configure the project to use Elixir 1.8.0
2. Place a breakpoint
3. Run the debugger
4. When suspended, click Evaluate expression
5. Type some valid code
6. Debugger crashes

Expected behavior
code gets evaluated

Logs

** (UndefinedFunctionError) function :elixir.quoted_to_erl/3 is undefined or private
    (elixir) :elixir.quoted_to_erl({:category, [line: 1], nil}, %Macro.Env{aliases: [], context: nil, context_modules: [], contextual_vars: [], current_vars: %{{:category, nil} => {0, :term}, {:filter, nil} => {0, :term}, {:session, nil} => {0, :term}}, file: "/filepath.ex", function: {:select_filter, 3}, functions: [{Kernel, [!=: 2, !==: 2, *: 2, +: 1, +: 2, ++: 2, -: 1, -: 2, --: 2, /: 2, <: 2, <=: 2, ==: 2, ===: 2, =~: 2, >: 2, >=: 2, abs: 1, apply: 2, apply: 3, binary_part: 3, bit_size: 1, byte_size: 1, ceil: 1, div: 2, elem: 2, exit: 1, floor: 1, function_exported?: 3, get_and_update_in: 3, get_in: 2, hd: 1, inspect: 1, inspect: 2, is_atom: 1, is_binary: 1, is_bitstring: 1, is_boolean: 1, is_float: 1, ...]}], lexical_tracker: nil, line: 126, macro_aliases: [], macros: [{Kernel, [!: 1, &&: 2, ..: 2, <>: 2, @: 1, alias!: 1, and: 2, binding: 0, binding: 1, def: 1, def: 2, defdelegate: 2, defexception: 1, defguard: 1, defguardp: 1, defimpl: 2, defimpl: 3, defmacro: 1, defmacro: 2, defmacrop: 1, defmacrop: 2, defmodule: 2, defoverridable: 1, defp: 1, defp: 2, defprotocol: 2, defstruct: 1, destructure: 2, get_and_update_in: 2, if: 2, in: 2, is_nil: 1, match?: 2, or: 2, pop_in: 1, ...]}], module: Mymodule, prematch_vars: :warn, requires: [Kernel, Kernel.Typespec], unused_vars: %{}, vars: [category: nil, filter: nil, session: nil]}, {:elixir_erl, nil, nil, false, %{{:category, nil} => {0, :_category@1}, {:filter, nil} => {0, :_filter@1}, {:session, nil} => {0, :_session@1}}, nil, [], %{category: 1, filter: 1, session: 1}, false})
    /tmp/intellij_elixir6/debugger/lib/intellij_elixir/debugger/server.ex:259: IntelliJElixir.Debugger.Server.handle_call/3
    (stdlib) gen_server.erl:661: :gen_server.try_handle_call/4
    (stdlib) gen_server.erl:690: :gen_server.handle_msg/6
    (stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3
Last message (from #PID<10473.5.0>): {:evaluate, %{env: %{file: "/filepath.ex", function: {:select_filter, 3}, line: 126, module: Mymodule}, expression: "category", pid: #PID<0.4175.0>, stack_pointer: 2}}
State: %IntelliJElixir.Debugger.Server{attached: #PID<10473.5.0>, evaluate_meta_pid_to_froms: %{}}
Client #PID<10473.5.0> is remote on node :"debuggerb121805e-0c71-447b-9b35-f082fc17e765@127.0.0.1"

Desktop:

• OS: Ubuntu Linux
• Version 18.04

Erlang:

• Installer asdf
• Version 21.2.3

Elixir:

• Installer asdf
• Version 1.8.1-otp-21

Plugin:

• Version v10.3.0

Additional context
plugin code links to here: https://github.com/elixir-lang/elixir/blob/8a971fcb44391bd8b16456666f3033b633c6ff77/lib/elixir/src/elixir.erl#L256
where we can see :elixir.quoted_to_erl/3 on top of the file in exports, but on branch v1.8 it's gone and there's only quoted_to_erl/2:
https://github.com/elixir-lang/elixir/blob/v1.8/lib/elixir/src/elixir.erl#L7

[michallepicki]

Awesome, thanks! Should we ask the Elixir team to have a stable documented interface for this kind of workflow?

[KronicDeth]

No, José has specifically told me that no one should be using these APIs and they are unsupported, but that he is fine if I use them.