I have attempted to debug this for a while but had no luck. I am running Ubutnu 20.04 using i3 for a window manager. This problem is occurring if I use the dmenu to launch VSCode or if I launch VSCode from the terminal.

I have installed Erlang / Elixir using asdf. asdf current says:

elixir 1.13.0-rc.1-otp-24 /home/luke/.tool-versions
erlang 24.1.6 /home/luke/.tool-versions

I am using i3 for a window manager and launch vscode using the dmenu. In a terminal within VSCode elixir --version yields:

Erlang/OTP 24 [erts-12.1.5] [source] [64-bit] [smp:32:32] [ds:32:32:10] [async-threads:1] [jit]
Elixir 1.13.0-rc.1 (2765e0f) (compiled with Erlang/OTP 24)

ElixirLS is detecting problems with the code however code completion is not working, and when I press ctrl-space I get the following error:

Failed to run ‘elixir’ command. ElixirLS will probably fail to launch. Logged PATH to Development Console.

echo $PATH in VSCode terminal shows:

home/luke/.asdf/shims:/home/luke/.asdf/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

Finally, here’s the ElixirLS output:

Started ElixirLS v0.8.1
Elixir version: "1.13.0-rc.1 (2765e0f) (compiled with Erlang/OTP 24)"
Erlang version: "24"
ElixirLS compiled with Elixir 1.10.4 and erlang 22
MIX_ENV: test
MIX_TARGET: 
[Error - 5:28:45 PM] Request textDocument/foldingRange failed.
  Message: an exception was raised:
    ** (CaseClauseError) no case clause matching: {:ok, 63, 1, [], [{:identifier, {1, 1, nil}, :defmodule}, {:alias, {1, 11, nil}, :Resourceq}, {:., {1, 20, nil}}, {:alias, {1, 21, nil}, :Schema}, {:., {1, 27, nil}}, {:alias, {1, 28, nil}, :Command}, {:do, {1, 36, nil}}, {:eol, {1, 38, 1}}, {:identifier, {2, 3, nil}, :use}, {:alias, {2, 7, nil}, :Ecto}, {:., {2, 11, nil}}, {:alias, {2, 12, nil}, :Schema}, {:eol, {2, 18, 2}}, {:identifier, {4, 3, nil}, :import}, {:alias, {4, 10, nil}, :Ecto}, {:., {4, 14, nil}}, {:alias, {4, 15, nil}, :Changeset}, {:eol, {4, 24, 2}}, {:identifier, {6, 3, nil}, :alias}, {:alias, {6, 9, nil}, :Resourceq}, {:., {6, 18, nil}}, {:alias, {6, 19, nil}, :Utils}, {:., {6, 24, nil}}, {:alias, {6, 25, nil}, :SchemaValidation}, {:eol, {6, 41, 1}}, {:identifier, {7, 3, nil}, :alias}, {:alias, {7, 9, nil}, :Resourceq}, {:., {7, 18, nil}}, {:alias, {7, 19, nil}, :Schema}, {:., {7, 25, nil}}, {:alias, {7, 26, nil}, :Command}, {:eol, {7, 33, 1}}, {:at_op, {10, 3, nil}, :@}, {:identifier, {10, 4, nil}, :primary_key}, {:"{", {10, 16, nil}}, {:atom, {10, 17, nil}, :uuid}, {:",", {10, 22, 0}}, {:atom, {10, 24, nil}, :binary_id}, {:",", {10, 34, 0}}, {:"[", {10, 36, nil}}, {:"]", {10, 37, ...}}, {:"}", {10, ...}}, {:eol, {...}}, {:at_op, ...}, {...}, ...]}
        (elixir_sense 2.0.0) lib/elixir_sense/core/normalized/tokenizer.ex:16: ElixirSense.Core.Normalized.Tokenizer.do_tokenize_1_7/1
        (language_server 0.8.1) lib/language_server/providers/folding_range/token.ex:18: ElixirLS.LanguageServer.Providers.FoldingRange.Token.format_string/1
        (language_server 0.8.1) lib/language_server/providers/folding_range.ex:119: ElixirLS.LanguageServer.Providers.FoldingRange.convert_text_to_input/1
        (language_server 0.8.1) lib/language_server/providers/folding_range.ex:97: ElixirLS.LanguageServer.Providers.FoldingRange.do_provide/1
        (language_server 0.8.1) lib/language_server/server.ex:808: anonymous fn/3 in ElixirLS.LanguageServer.Server.handle_request_async/2
  Code: -32000 

17:28:45.597 [error] Process #PID<0.123.0> raised an exception
** (CaseClauseError) no case clause matching: {:ok, 63, 1, [], [{:identifier, {1, 1, nil}, :defmodule}, {:alias, {1, 11, nil}, :Resourceq}, {:., {1, 20, nil}}, {:alias, {1, 21, nil}, :Schema}, {:., {1, 27, nil}}, {:alias, {1, 28, nil}, :Command}, {:do, {1, 36, nil}}, {:eol, {1, 38, 1}}, {:identifier, {2, 3, nil}, :use}, {:alias, {2, 7, nil}, :Ecto}, {:., {2, 11, nil}}, {:alias, {2, 12, nil}, :Schema}, {:eol, {2, 18, 2}}, {:identifier, {4, 3, nil}, :import}, {:alias, {4, 10, nil}, :Ecto}, {:., {4, 14, nil}}, {:alias, {4, 15, nil}, :Changeset}, {:eol, {4, 24, 2}}, {:identifier, {6, 3, nil}, :alias}, {:alias, {6, 9, nil}, :Resourceq}, {:., {6, 18, nil}}, {:alias, {6, 19, nil}, :Utils}, {:., {6, 24, nil}}, {:alias, {6, 25, nil}, :SchemaValidation}, {:eol, {6, 41, 1}}, {:identifier, {7, 3, nil}, :alias}, {:alias, {7, 9, nil}, :Resourceq}, {:., {7, 18, nil}}, {:alias, {7, 19, nil}, :Schema}, {:., {7, 25, nil}}, {:alias, {7, 26, nil}, :Command}, {:eol, {7, 33, 1}}, {:at_op, {10, 3, nil}, :@}, {:identifier, {10, 4, nil}, :primary_key}, {:"{", {10, 16, nil}}, {:atom, {10, 17, nil}, :uuid}, {:",", {10, 22, 0}}, {:atom, {10, 24, nil}, :binary_id}, {:",", {10, 34, 0}}, {:"[", {10, 36, nil}}, {:"]", {10, 37, ...}}, {:"}", {10, ...}}, {:eol, {...}}, {:at_op, ...}, {...}, ...]}
    (elixir_sense 2.0.0) lib/elixir_sense/core/normalized/tokenizer.ex:16: ElixirSense.Core.Normalized.Tokenizer.do_tokenize_1_7/1
    (language_server 0.8.1) lib/language_server/providers/folding_range/token.ex:18: ElixirLS.LanguageServer.Providers.FoldingRange.Token.format_string/1
    (language_server 0.8.1) lib/language_server/providers/folding_range.ex:119: ElixirLS.LanguageServer.Providers.FoldingRange.convert_text_to_input/1
    (language_server 0.8.1) lib/language_server/providers/folding_range.ex:97: ElixirLS.LanguageServer.Providers.FoldingRange.do_provide/1
    (language_server 0.8.1) lib/language_server/server.ex:808: anonymous fn/3 in ElixirLS.LanguageServer.Server.handle_request_async/2
[Info  - 5:28:45 PM] Compile took 401 milliseconds
[Info  - 5:28:45 PM] [ElixirLS WorkspaceSymbols] Indexing...
[Info  - 5:28:45 PM] [ElixirLS Dialyzer] Checking for stale beam files
[Info  - 5:28:46 PM] [ElixirLS WorkspaceSymbols] Module discovery complete
[Info  - 5:28:46 PM] [ElixirLS WorkspaceSymbols] 22 callbacks added to index
[Info  - 5:28:46 PM] [ElixirLS WorkspaceSymbols] 197 modules added to index
[Info  - 5:28:46 PM] [ElixirLS Dialyzer] Found 2 changed files in 73 milliseconds
[Info  - 5:28:46 PM] [ElixirLS Dialyzer] Analyzing 8 modules: [Resourceq.Application, Resourceq.CommandWorker, Resourceq.Commands, Resourceq.Schema.Command, ResourceqWeb.CommandController, ResourceqWeb.Endpoint, ResourceqWeb.EventsChannel, ResourceqWeb.Router]
[Info  - 5:28:46 PM] [ElixirLS WorkspaceSymbols] 285 types added to index
[Info  - 5:28:46 PM] [ElixirLS Dialyzer] Analysis finished in 333 milliseconds
[Info  - 5:28:46 PM] Dialyzer analysis is up to date