[BUG] workspaceSymbol LSP operation crashes with undefined is not an object (evaluating 'f.location.range.start')

Resolved 💬 1 comment Opened May 8, 2026 by gasrodriguez Closed Jun 7, 2026

Preflight Checklist

  • [x] I have searched existing issues and this hasn't been reported yet
  • [x] This is a single bug report (please file separate reports for different bugs)
  • [x] I am using the latest version of Claude Code

What's Wrong?

Disclaimer: I'm filling this bug report on behalf of Claude Code, I first asked if could possibly be a bug with the lang server that I use slang-server and it honestly said no, and provided a potential fix too.

---
Conclusion: this is a Claude Code client bug, not a Slang bug. Slang is probably spec-compliant. The report should go to the Claude Code team, not the Slang developer. The fix is to guard against missing range:

// before:
f.location.range.start

// after:
f.location.range?.start

---
The operation crashes before returning any results, making workspace-wide symbol search completely unusable. The client code unconditionally accesses f.location.range.start but LSP 3.17 allows WorkspaceSymbol.location to omit range (partial location, resolved lazily via workspaceSymbol/resolve). When a compliant server returns the partial form, the access throws undefined is not an object (evaluating 'f.location.range.start').

What Should Happen?

workspaceSymbol should return a list of matching symbols with their file locations, allowing navigation to any symbol definition across the workspace without reading files manually.

Error Messages/Logs

Error performing workspaceSymbol: undefined is not an object (evaluating 'f.location.range.start')

Steps to Reproduce

  1. Open a project with a Slang language server configured
  2. Call the workspaceSymbol LSP operation on any file

This is the LSP config of my plugin:

{
  "systemverilog": {
    "command": "slang-server",
    "args": [],
    "extensionToLanguage": {
      ".sv": "systemverilog",
      ".svh": "systemverilog",
      ".v": "verilog",
      ".vh": "verilog"
    }
  }
}

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.136 (Claude Code)

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_

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