Language server no longer starts up after upgrading to Elixir 1.18.4

[wheredoipressnow]

Language server no longer starts up after upgrading to Elixir 1.18.4. (OTP 27)
Windows machine.
Downgrading instantly resolves the issue.

I'd really appreciate any suggestions on how to fix or troubleshoot it further!

2025-05-28T06:23:19.880 helix_lsp::transport [ERROR] elixir-ls err <- "Installing ElixirLS release v0.28.0\n"
2025-05-28T06:23:19.880 helix_lsp::transport [ERROR] elixir-ls err <- "Running in c:/retracted_internal_name/project_umbrella\n"
2025-05-28T06:23:19.914 helix_lsp::transport [ERROR] elixir-ls err <- "* Updating elixir_ls (https://github.com/elixir-lsp/elixir-ls.git - v0.28.0)\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "Mix.install failed with ** (Mix.Error) Command \"git --git-dir=.git checkout --force --quiet v0.28.0\" failed with reason: error: unable to create file apps/language_server/test/fixtures/umbrella_test_code_lens_custom_path_and_pattern/apps/app1/custom_path/fixture_custom_test.exs: Filename too long\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix.ex:618: Mix.raise/2\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/scm/git.ex:140: Mix.SCM.Git.checkout/2\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (elixir 1.18.4) lib/file.ex:1665: File.cd!/2\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/fetcher.ex:65: Mix.Dep.Fetcher.do_fetch/3\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:238: Mix.Dep.Converger.all/9\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:170: Mix.Dep.Converger.init_all/8\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:110: Mix.Dep.Converger.all/4\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:89: Mix.Dep.Converger.converge/4\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "\n"
2025-05-28T06:23:21.138 helix_lsp::transport [ERROR] elixir-ls err <- "Retrying Mix.install with force: true\n"
2025-05-28T06:23:21.139 helix_lsp::transport [ERROR] elixir-ls err <- "Installing ElixirLS release v0.28.0\n"
2025-05-28T06:23:21.139 helix_lsp::transport [ERROR] elixir-ls err <- "Running in c:/retracted_internal_name/project_umbrella\n"
2025-05-28T06:23:21.375 helix_lsp::transport [ERROR] elixir-ls err <- "* Getting elixir_ls (https://github.com/elixir-lsp/elixir-ls.git - v0.28.0)\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "** (Mix.Error) Command \"git --git-dir=.git checkout --force --quiet v0.28.0\" failed with reason: error: unable to create file apps/language_server/test/fixtures/umbrella_test_code_lens_custom_path_and_pattern/apps/app1/custom_path/fixture_custom_test.exs: Filename too long\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix.ex:618: Mix.raise/2\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/scm/git.ex:140: Mix.SCM.Git.checkout/2\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (elixir 1.18.4) lib/file.ex:1665: File.cd!/2\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/fetcher.ex:68: Mix.Dep.Fetcher.do_fetch/3\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:238: Mix.Dep.Converger.all/9\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:170: Mix.Dep.Converger.init_all/8\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:110: Mix.Dep.Converger.all/4\n"
2025-05-28T06:23:24.481 helix_lsp::transport [ERROR] elixir-ls err <- "    (mix 1.18.4) lib/mix/dep/converger.ex:89: Mix.Dep.Converger.converge/4\n"
2025-05-28T06:23:24.496 helix_lsp [ERROR] failed to initialize language server: server closed the stream
2025-05-28T06:23:24.496 helix_lsp::transport [ERROR] elixir-ls err: <- StreamClosed

[lukaszsamson]

I'd really appreciate any suggestions on how to fix or troubleshoot it further!

You have the error message right here. It doesn't look like ElixirLS problem

Mix.install failed with ** (Mix.Error) Command \"git --git-dir=.git checkout --force --quiet v0.28.0\" failed with reason: error: unable to create file apps/language_server/test/fixtures/umbrella_test_code_lens_custom_path_and_pattern/apps/app1/custom_path/fixture_custom_test.exs: Filename too long\n"

[wheredoipressnow]

Yes. Reverting to Elixir 1.17 resolves the issue. Nothing else changes. Please correct me if I am wrong but this process depends on the installed Elixir version?

[wheredoipressnow]

Do I understand you correctly, do you suggest this is an issue with mix and the latest Elixir version?

[wheredoipressnow]

I opened elixir-lang/elixir#14543

Leaving it here in case somebody else encounters the same issue.