VS Code extension error Request textDocument/codeAction failed when using dbg

[SDepn]

I am getting a VS Code error Request textDocument/codeAction failed. whenever I try to put |> dbg behind any kind of function. It does not seem to matter what function it is, it happens every time. I had this in my work project and was able to reproduce it in a test project as well.

For example if I have this code:

  def my_function do
    foo()
  end

As soon as I try to |> dbg behind the foo() function call, I get the error.

This is the log output for the error:

2026-04-08 14:45:54.942 [info] [Info  - 2:45:54 PM] Opened file:///home/<USER>/dev/test_project/lib/test_project/documents.ex
2026-04-08 14:45:54.958 [info] [Info  - 2:45:54 PM] Resolved entity: {:call, Kernel, :defmodule, 2}
2026-04-08 14:45:59.493 [info] [Info  - 2:45:59 PM] Emitting Completions: [:do/end block ]
2026-04-08 14:45:59.713 [info] [Info  - 2:45:59 PM] Completion for XpPos<<104, 54>>
2026-04-08 14:45:59.719 [info] [Warn  - 2:45:59 PM] Unhandled trace event: {:compile_env, :elixir, [:dbg_callback], {:ok, {Macro, :dbg, []}}}
2026-04-08 14:45:59.720 [info] [Warn  - 2:45:59 PM] Unhandled trace event: {:compile_env, :elixir, [:dbg_callback], {:ok, {Macro, :dbg, []}}}
2026-04-08 14:45:59.759 [info] [Info  - 2:45:59 PM] Local completions are: [macro: (dbg, dbg, dbg)   ]
2026-04-08 14:45:59.768 [info] [Info  - 2:45:59 PM] Emitting Completions: [3:dbg() 3:dbg(options) ]
2026-04-08 14:46:00.073 [info] [Info  - 2:46:00 PM] Resolved entity: {:call, Kernel, :dbg, 0}
2026-04-08 14:46:00.260 [info] [Error - 2:46:00 PM] ** (ErlangError) Erlang error: {:exception, :function_clause, [{:lists, :mapfoldl_1, [#Function<20.36417308/2 in Macro>, %{last_line: 104}, nil], [file: ~c"lists.erl", line: 2672]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2674]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2673]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2673]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2674]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}]}
    (kernel 10.2.7.1) erpc.erl:1368: :erpc.call/5
    (xp_expert 0.1.0) lib/expert/provider/handlers/code_action.ex:19: XPExpert.Provider.Handlers.CodeAction.handle/1
    (xp_expert 0.1.0) lib/expert.ex:118: XPExpert.handle_request/2
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:390: anonymous fn/2 in XPGenLSP.loop/3
    (xp_telemetry 1.3.0) /Users/runner/work/expert/expert/apps/expert/deps/telemetry/src/telemetry.erl:324: :xp_telemetry.span/3
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:389: anonymous fn/5 in XPGenLSP.loop/3
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:559: anonymous fn/4 in XPGenLSP.attempt/4
    (elixir 1.17.3) lib/task/supervised.ex:101: Task.Supervised.invoke_mfa/2
2026-04-08 14:46:00.261 [info] [Error - 2:46:00 PM] ** (ErlangError) Erlang error: {:exception, :function_clause, [{:lists, :mapfoldl_1, [#Function<20.36417308/2 in Macro>, %{last_line: 104}, nil], [file: ~c"lists.erl", line: 2672]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2674]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2673]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2673]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2674]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}]}
    (kernel 10.2.7.1) erpc.erl:1368: :erpc.call/5
    (xp_expert 0.1.0) lib/expert/provider/handlers/code_action.ex:19: XPExpert.Provider.Handlers.CodeAction.handle/1
    (xp_expert 0.1.0) lib/expert.ex:118: XPExpert.handle_request/2
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:390: anonymous fn/2 in XPGenLSP.loop/3
    (xp_telemetry 1.3.0) /Users/runner/work/expert/expert/apps/expert/deps/telemetry/src/telemetry.erl:324: :xp_telemetry.span/3
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:389: anonymous fn/5 in XPGenLSP.loop/3
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:559: anonymous fn/4 in XPGenLSP.attempt/4
    (elixir 1.17.3) lib/task/supervised.ex:101: Task.Supervised.invoke_mfa/2

2026-04-08 14:46:00.261 [info] [Error - 2:46:00 PM] Request textDocument/codeAction failed.
2026-04-08 14:46:00.261 [info]   Message: ** (ErlangError) Erlang error: {:exception, :function_clause, [{:lists, :mapfoldl_1, [#Function<20.36417308/2 in Macro>, %{last_line: 104}, nil], [file: ~c"lists.erl", line: 2672]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2674]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2673]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2673]}, {:lists, :mapfoldl_1, 3, [file: ~c"lists.erl", line: 2674]}, {Macro, :do_traverse, 4, [file: ~c"lib/macro.ex", line: 628]}]}
    (kernel 10.2.7.1) erpc.erl:1368: :erpc.call/5
    (xp_expert 0.1.0) lib/expert/provider/handlers/code_action.ex:19: XPExpert.Provider.Handlers.CodeAction.handle/1
    (xp_expert 0.1.0) lib/expert.ex:118: XPExpert.handle_request/2
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:390: anonymous fn/2 in XPGenLSP.loop/3
    (xp_telemetry 1.3.0) /Users/runner/work/expert/expert/apps/expert/deps/telemetry/src/telemetry.erl:324: :xp_telemetry.span/3
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:389: anonymous fn/5 in XPGenLSP.loop/3
    (xp_gen_lsp 0.11.3) lib/gen_lsp.ex:559: anonymous fn/4 in XPGenLSP.attempt/4
    (elixir 1.17.3) lib/task/supervised.ex:101: Task.Supervised.invoke_mfa/2

  Code: -32603 
2026-04-08 14:46:03.510 [info] [Info  - 2:46:03 PM] Resolved entity: {:call, Kernel, :dbg, 0}
2026-04-08 14:46:09.367 [info] [Info  - 2:46:09 PM] Compiled test_project in 169 ms

## Specs

IDE: Visual Studio Code (1.114.0)
Installation method: VS Code Extension store
Expert version: v0.1.0
OS: Windows with WSL (project and VS code running in WSL)
OTP / Elixir version: 28.3.1 / 1.19.5 installed with ASDF