MCP Debugger

# JavaScript Docker Debugging Issue Summary ## Problem JavaScript debugging in Docker fails with "Proxy exited during initialization. Code: 1, Signal: SIGTERM" ## Current Status ### What's Working 1. ✅ File exists at `/workspace/examples/javascript/mcp_target.js` 2. ✅ Node.js v20.19.5 is available in container 3. ✅ js-debug vendor files are present at `/app/packages/adapter-javascript/vendor/js-debug/` 4. ✅ Environment variables set correctly (MCP_CONTAINER=true, MCP_WORKSPACE_ROOT=/workspace) 5. ✅ Python debugging works in the same container setup 6. ✅ Tini is installed and configured as entrypoint for proper signal handling ### The Issue The proxy process starts but immediately receives SIGTERM during initialization: ``` [Proxy Worker] Starting DAP Proxy worker process... [Proxy Worker] Node.js version: v20.19.5 [Proxy Worker] Current working directory: / [INFO] [ProxyRunner] Starting proxy runner... [INFO] [ProxyRunner] Ready to receive commands [Signal Debug] Setting up signal handlers for session... [Signal Debug] Signal handlers installed ``` Then the process receives SIGTERM and exits. ### Path Resolution Flow 1. Test provides path: `examples/javascript/mcp_target.js` (relative) 2. SimpleFileChecker resolves to: `/workspace/examples/javascript/mcp_target.js` (absolute) 3. This path is passed to JavaScript adapter 4. JavaScript adapter launches the proxy with this path ### Key Difference from Python - Python adapter receives `/workspace/examples/javascript/mcp_target.js` and it works - JavaScript adapter receives the same path but the proxy exits with SIGTERM ### Hypothesis The JavaScript adapter or the proxy might be having issues with: 1. The working directory being `/` instead of `/workspace` 2. The executable path for Node.js (`/usr/bin/node`) 3. Some other initialization parameter ## Next Steps 1. Check what command the JavaScript adapter is actually running 2. Verify the proxy can handle absolute paths starting with `/workspace` 3. Check if there's a working directory issue