Introducing ElixirLS, the Elixir Language Server

0.6.4 was released today which has a hotfix for a startup issue that was primarily affecting macOS:


0.6.5 was released to which has a hotfix for a regression introduced in 0.6.3:

This would often manifest when VSCode had staged or unstaged changes.


Version 0.7.0 was released today! :confetti_ball:

Here are the highlights:

Major Changes:

  • Support auto-generating folding ranges (textDocument/foldingRange) (thanks billylanchantin (inspired by an initial PR by Thanabodee Charoenpiriyakij) #492

    • Example: Screenshot 2021-03-29 08.15.31
    • For VSCode this will work automatically, other editors may need to enable LSP folding range support explicitly
  • Use fuzzy matching for function completion (thanks Po Chen) #491

    • For example: “valp” will match validate_password and “Enum.chub” will match Enum.chunk_by/2
    • Note: the plan is to extend this fuzzy matching to other types of completion in the future, please try it out and give us feedback!


Bug Fixes:

  • Make expandMacro a custom command (thanks Łukasz Samson) #498
    • Will need to be bound in your editor to make use of it
  • Suppress setup script stdout output on windows(thanks Po Chen) #497


  • Improved support for OTP 24 (thanks Tom Crossland) #504
    • Note that OTP 24 isn’t officially supported since it is not yet released


Deprecate non-standard elixirDocument/macroExpansion command. It is being replaced with the expandMacro custom command. See #498 for details. It is planned to be fully removed in 0.8

As always, I want to give a huge thanks to all the contributors to this release! :heart:

Full changelog


Hi Jason,

There is a minor error in the description about the fuzzy matching. valword will actually match validate_password. The first character restriction is only applied to the very first character of the whole function name. If the trigger word doesn’t start with v it would not match, like if one types dw wouldn’t get validate_password, but vpw, vp or vw will.


Thanks, updated!

1 Like

Tried to scan the issue tracker for what I am experiencing for a week or two now, can’t find anything (might be me though, I am not sure what exactly to search with).

But basically using Erlang 24.0.2 and Elixir 1.12.1-otp-24 reliably crashes ElixirLS as far as I can tell. Here’s a hopefully relevant excerpt from my Spacemacs’ *lsp-log* buffer:

19:39:41.324 [error] Task #PID<0.261.0> started from #PID<0.217.0> terminating
** (ArithmeticError) bad argument in arithmetic expression
    (language_server 0.6.0) lib/language_server/providers/workspace_symbols.ex:519: ElixirLS.LanguageServer.Providers.WorkspaceSymbols.build_range/1
    (language_server 0.6.0) lib/language_server/providers/workspace_symbols.ex:487: ElixirLS.LanguageServer.Providers.WorkspaceSymbols.build_result/4
    (language_server 0.6.0) lib/language_server/providers/workspace_symbols.ex:397: anonymous fn/4 in ElixirLS.LanguageServer.Providers.WorkspaceSymbols.index/1
    (elixir 1.12.1) lib/enum.ex:2356: Enum."-reduce/3-lists^foldl/2-0-"/3
    (language_server 0.6.0) lib/language_server/providers/workspace_symbols.ex:386: anonymous fn/1 in ElixirLS.LanguageServer.Providers.WorkspaceSymbols.index/1
    (elixir 1.12.1) lib/task/supervised.ex:90: Task.Supervised.invoke_mfa/2
    (elixir 1.12.1) lib/task/supervised.ex:35: Task.Supervised.reply/5
    (stdlib 3.15.1) proc_lib.erl:226: :proc_lib.init_p_do_apply/3
Function: #Function<32.57814553/0 in ElixirLS.LanguageServer.Providers.WorkspaceSymbols.do_process_chunked/2>
    Args: []
** (exit) exited in:, {:packet, %{"id" => 137, "jsonrpc" => "2.0", "method" => "textDocument/hover", "params" => %{"position" => %{"character" => 19, "line" => 7}, "textDocument" => %{"uri" => "file:///Users/dimi/kod/square-many/mix.exs"}}}}, 5000)
    ** (EXIT) no process: the process is not alive or there's no process currently associated with the given name, possibly because its application isn't started
    (elixir 1.12.1) lib/gen_server.ex:1014:
    (elixir 1.12.1) lib/stream.ex:441: anonymous fn/4 in Stream.each/2
    (elixir 1.12.1) lib/stream.ex:1559: Stream.do_element_resource/6
    (elixir 1.12.1) lib/stream.ex:1719: Enumerable.Stream.do_each/4
    (elixir 1.12.1) lib/stream.ex:649:
    (stdlib 3.15.1) erl_eval.erl:685: :erl_eval.do_apply/6
Cleaning up watches for folder /Users/dimi/kod/square-many. There is no workspace watching this folder...

(The first part ([error] Task #PID ...) is repeated several times.)

This is a brand new bare-bones project, without application.ex even. But the same happens with any other projects I tried with.

Anything I can do? I am always using elixir-lsp/elixir-ls GitHub HEAD btw, and I am updating it daily from there. Maybe I shouldn’t and I should just latest stable release? Or maybe ElixirLS isn’t yet compatible with Erlang 24 / Elixir 1.12?

Can you confirm which specific commit that you are using? Perhaps you didn’t run mix elixir_ls.release after running git pull. I ask because ElixirLS is currently on 0.7.0 (your stack trace lists 0.6.0) and it looks like you’re running into this OTP 24 compatibility error: Compatibility with OTP 24 · Issue #503 · elixir-lsp/elixir-ls · GitHub

Which was fixed in March:

1 Like


* be0af9d - (HEAD -> master, origin/master, origin/HEAD) Update README troubleshooting and known issues (#554) (3 days ago) <Jason Axelson>

Had to run mix deps.get first. After running mix elixir_ls.release, I got this:

# ...
# compiling other deps before this finishes successfully
# ...
==> elixir_sense
Compiling 54 files (.ex)
Generated elixir_sense app
warning: Building with Erlang/OTP 24. Make sure to build with OTP 21 if publishing the compiled packages because modules built with higher versions are not backwards-compatible.

** (ErlangError) Erlang error: {:invalid_status, :compile}
    (mix_task_archive_deps 0.4.0) lib/mix/tasks/archive/build.deps.ex:78: anonymous fn/3 in Mix.Tasks.Archive.Build.Deps.list/1
    (elixir 1.12.1) lib/enum.ex:1553: Enum."-map/2-lists^map/1-0-"/2
    (elixir 1.12.1) lib/enum.ex:1553: Enum."-map/2-lists^map/1-0-"/2
    (mix_task_archive_deps 0.4.0) lib/mix/tasks/archive/build.deps.ex:53: Mix.Tasks.Archive.Build.Deps.build_archives/1
    (mix 1.12.1) lib/mix/task.ex:394: anonymous fn/3 in Mix.Task.run_task/3
    (mix 1.12.1) lib/mix/task.ex:394: anonymous fn/3 in Mix.Task.run_task/3
    (mix 1.12.1) lib/mix/cli.ex:84: Mix.CLI.run_task/2

asdf current returns:

elixir          1.12.1-otp-24   /Users/dimi/.tool-versions
erlang          24.0.2          /Users/dimi/.tool-versions
nodejs          15.14.0         /Users/dimi/.tool-versions

That’s a bug in the archive does library. I think it’s fixed with a rm -r _build, although you might have to remove some tmp directories from the individual applications. There’s a closed issue for it but I don’t have the link handy.

1 Like

Okay, removing _build worked. I got a bunch of .ez archives in the release directory now. Anything else I should do?

I am asking this because I am after a daily script that updates ElixirLS and want to have all the steps put there.

Seems like I don’t have to do anything extra, only restart my Emacs because it didn’t pick up the changes in ElixirLS upon reloading a buffer. But after that it did build the project with Erlang 24 / Elixir 1.12.



OK, here’s another question (or a request):

Can ElixirLS have several different releases compiled for different OTP versions and switch between them depending on which OTP version the project uses?

I have several projects that aren’t moving away to OTP 24 anytime soon and when I compile ElixirLS for it those projects’ LSP startup fails (I guess unsurprisingly). So I recompiled ElixirLS for OTP 23 but that will crash it when starting it inside OTP 24 projects.

After visiting an OTP 23 projects while ElixirLS is compiled for OTP 24 I get an error on the lane of “can’t find ElixirLS CLI module” or some such (can dig the error if you like).

Version 0.8.0 was released today! :rocket:

Note that there are some deprecations in this release:

This release adds HEEx and Surface file support to ElixirLS, but for syntactical support VSCode users will want to wait for GitHub - phoenixframework/vscode-phoenix which is still under development (ElixirLS itself doesn’t contain syntax support, that’s generally provided by an editor-specific extension).


Bug Fixes:



Note: There is beta support for a pipe/unpipe command (which I am very excited about), but it is not fully exposed in vscode-elixir-ls

As always, I want to give a huge thanks to all the contributors to this release!

Full Changelog


I believe it could, but someone would have to put in the work to make that work (and there was an emacs extension that supported that previously, although it was not automatic). Here’s the main packaging issue for reference: Discussion: Change packaging approach · Issue #115 · elixir-lsp/elixir-ls · GitHub

1 Like

Thanks to you & the other contributors for all your work. It makes the experience of learning & using Elixir far more pleasant than it would otherwise be. I for one am appreciative and hope to be able to give back in kind at some point :vulcan_salute:


Hi @axelson :slight_smile: What are those pipe/unpipe commands you’re referring to please?

I’m just guessing here, but could be a refactor command to remove pipes or create pipes from function calls.

1 Like

@cpgo is correct! And that feature will hopefully be ready for the next release :+1: