Language server crashes with error "got more than 100 headers" when `MIX_OS_DEPS_COMPILE_PARTITION_COUNT` is set for Elixir `1.19.0-rc.0`

[Eiji7]

I saw that you are not officially supporting release candidates. I'm just trying many pet projects and tools on new releases and sometimes even on specific commits. Since it was a serious problem for me for the longer time I've decided to share it, so others does not have to waste so much time on this cryptic error.

This is the only information in the editor console:

LSP: lsp-elixir crashed (1 / 5 times in the last 180.0 seconds), exit code 0, exception: "got more than 100 headers"
LSP: lsp-elixir crashed (2 / 5 times in the last 180.0 seconds), exit code 0, exception: "got more than 100 headers"
LSP: lsp-elixir crashed (3 / 5 times in the last 180.0 seconds), exit code 0, exception: "got more than 100 headers"
LSP: lsp-elixir crashed (4 / 5 times in the last 180.0 seconds), exit code 0, exception: "got more than 100 headers"
LSP: lsp-elixir crashed (5 / 5 times in the last 180.0 seconds), exit code 0, exception: "got more than 100 headers"

I found that unsetting MIX_OS_DEPS_COMPILE_PARTITION_COUNT environment variable fixes the problem. I wonder if this can be fixed as I have no idea why this causes such an error. Is it an editor limitation or is it a bug in the language server itself?

Hopefully you can fix that soon and send a patch release if possible. Let me know if you need any help from me.

[lukaszsamson]

Nice find. I haven't tested MIX_OS_DEPS_COMPILE_PARTITION_COUNT with ElixirLS yet. My first guess is mix pollutes stdout or reads from stdin breaking LSP protocol