debug-info-remapping

Original：🇺🇸 English

Translated

1 scripts

Remap the function_id:pc_index to the original source code position by provided debug info json file.

4installs

Sourcelynx-community/skills

Added on2026-04-25

NPX Install

npx skill4agent add lynx-community/skills debug-info-remapping

SKILL.md Content

View Translation Comparison →

Debug Info Remapping

Description

In Lynx, main thread script is encoded to bytecode and uses an external debugging information scheme. Under this scheme, the row and column numbers in the runtime error messages are not the actual row and column numbers. The row and column numbers need to be deciphered from the external

debug-info.json

file.

debug-info.json format is as follows:

json

{
  "lepusNG_debug_info": {
    "function_info": [
      {
        "function_id": 1,
        "function_name": "App",
        "line_col": [
          { "line": 1, "column": 1 },
          { "line": 2, "column": 1 },
          { "line": 3, "column": 1 }
        ]
      }
    ]
  }
}

When to Apply

This skill is useful when you want to remap the

function_id:pc_index

to the original source code position.

When the user encounters a runtime error message with function_id:pc_index, along with

main-thread.js

and

debug-info.json

in the error message, for example:

main-thread.js exception: App render failed at main thread backtrace:
    at App (file:///main-thread.js:1356:13)
    at doRender (file:///main-thread.js:1002:12)
    at call (native)
    at render (file:///main-thread.js:466:52)
    at _renderToString (file:///main-thread.js:1001:569)
    at renderToString (file:///main-thread.js:998:191)
    at renderMainThread (file:///main-thread.js:766:45)
    at renderPage (file:///main-thread.js:853:69)

Where

function_id:pc_index

is

1356:13

.

Workflow

1. Ask the User for the

function_id:pc_index

User should provide the

function_id:pc_index

in the error message. Or give you the full backtrace.

You should check if it is a main-thread backtrace. Since background thread backtrace does not need remapping.

2. Find the Corresponding Position in debug-info.json

Ask the user for the

debug-info.json

path. For example in a rspeedy project with

main

entry it will locate at:

main-thread.js

:

$PROJECT_DIR/dist/.rspeedy/main/main-thread.js

debug-info.json

:

$PROJECT_DIR/dist/.rspeedy/main/debug-info.json

If the user uses

rspeedy build

and there is no

.rspeedy

folder, remind them to build the project with

DEBUG='rspeedy,rsbuild' rspeedy build

.

3. Run the remapping script

For each

function_id:pc_index

pair in the stack trace, run the remapping script.

bash

node ${CLAUDE_PLUGIN_ROOT}/skills/debug-info-remapping/scripts/index.mjs $PROJECT_DIR/[dist]/.rspeedy/[main]/debug-info.json $function_id $pc_index

4. Output the Remapped Position

The remapping script will output the remapped position in the format of

line:column

.

You should output the remapped position for each

function_id:pc_index

pair.

Replace the

function_id:pc_index

pair in the stack trace with the remapped position and show the remapped stack trace.

5. Show the Remapped Stack Trace

If you can reach the

main-thread.js

file, show the remapped stack trace with the remapped positions source code.

The final output should be something like this:

log

main-thread.js exception: App render failed at main thread backtrace:
    at App (./dist/.rspeedy/main/main-thread.js:9368:56)
    at doRender (./dist/.rspeedy/main/main-thread.js:7237:44)
    at call (native)
    at render (./dist/.rspeedy/main/main-thread.js:3706:72)
    at _renderToString (./dist/.rspeedy/main/main-thread.js:7177:78)
    at renderToString (./dist/.rspeedy/main/main-thread.js:7067:91)
    at renderMainThread (./dist/.rspeedy/main/main-thread.js:5423:113)
    at renderPage (./dist/.rspeedy/main/main-thread.js:6199:46)

   ╭─[5:55]
 3 │ export function App() {
 4 │   if (__MAIN_THREAD__) {
 5 │     throw new Error('App render failed at main thread');
   ·                                                      ─┬
   ·                                                       ╰── main-thread.js exception: App render failed at main thread backtrace
 6 │   }
 7 │
   ╰────

   ... (the same for other callstacks such as doRender, call, render, _renderToString, renderToString, renderMainThread, renderPage here)

Files used:

  - Debug Info: ./dist/.rspeedy/main/debug-info.json
  - Source File: ./dist/.rspeedy/main/main-thread.js

The

./dist/.rspeedy/main/main-thread.js:9368:56

will make sure it is clickable in the editor/terminal.