(UndefinedFunctionError) function ElixirLS.LanguageServer.main/0 is undefined (module ElixirLS.LanguageServer is not available)

[anildigital]

Precheck

Done

Environment

• Elixir & Erlang versions (elixir --version):

 elixir --version
Erlang/OTP 24 [erts-12.3.2.2] [source] [64-bit] [smp:10:10] [ds:10:10:10] [async-threads:1]

Elixir 1.13.3 (compiled with Erlang/OTP 23)

• Elixir Language Server version: v0.21.3

• Operating system: macOS Sonoma 14.5 (23F79)

• Editor or IDE name: Zed

• Editor Plugin/LSP Client name and version: elixir-ls plugin

Current behavior

 sh "/Users/anil/Library/Application Support/Zed/extensions/work/elixir/elixir-ls-v0.21.3/language_server.sh"
Running /Users/anil/Library/Application Support/Zed/extensions/work/elixir/elixir-ls-v0.21.3/launch.sh
Preferred shell is fish, launching launch.fish
Looking for ASDF install
ASDF install found in /opt/homebrew/opt/asdf/libexec/asdf.fish, sourcing
Installing ElixirLS release v0.21.3
Running in /Users/anil
Install complete
** (UndefinedFunctionError) function ElixirLS.LanguageServer.main/0 is undefined (module ElixirLS.LanguageServer is not available)
    ElixirLS.LanguageServer.main()
    Library/Application Support/Zed/extensions/work/elixir/elixir-ls-v0.21.3/launch.exs:18: (file)

Expected behavior

It should start the server

[lukaszsamson]

Please do some investigation. Something is broken on your machine.
What happens when you explicitly install in iex? Be sure to use the exact same elixir and otp

Mix.install(
      [
        {:elixir_ls, github: "elixir-lsp/elixir-ls", tag: "v0.21.3"}
      ],
      start_applications: false,
      consolidate_protocols: false
    )

It should succeed and then it should be able to start

iex(2)> ElixirLS.LanguageServer.main()
Content-Length: 103

{"jsonrpc":"2.0","method":"window/logMessage","params":{"message":"Started ElixirLS v0.21.3","type":3}}Content-Length: 116

Examine contents of your mix installs dir given by Mix.Utils.mix_cache() (usually /Users/<user>/Library/Caches/mix)
Check your elixir install. You use a version built for OTP 23 on OTP 24.

[anildigital]

I deleted folders inside /Users/anil/Library/Caches/mix and restarted Zed editor (which fetched elixir-ls plugin again). This fixed the issue.