DollhouseMCP

# Session: PR #606 ARM64 Docker Fix - Complete Success **Date**: August 17, 2025 **Time**: 2:00 PM - 4:30 PM EST **Branch**: `feature/search-index-implementation` **PR**: #606 - Search index implementation **Status**: ✅ ALL TESTS PASSING - Ready to merge ## Executive Summary Successfully resolved ARM64 Docker test failures by implementing native ARM64 runners, eliminating QEMU emulation overhead. Used multi-agent orchestration to identify root cause and implement solution. All Docker tests now pass and MCP server confirmed working with valid API responses. ## The Problem ARM64 Docker tests were failing with timeouts in GitHub Actions CI while working perfectly locally. This had been blocking PR #606 for almost a month. ## Multi-Agent Investigation & Solution ### Agent Orchestration (Opus Coordinating) Created `/docs/development/DOCKER_ARM64_FIX_COORDINATION.md` as central coordination document. #### Alpha (Local Docker Tester) - **Finding**: Both AMD64 and ARM64 work perfectly locally - **Build times**: AMD64: 0.67s, ARM64: 0.58s (cached) - **Runtime**: AMD64: ~0.1s, ARM64: ~0.28s response time - **Conclusion**: Issue is CI-specific, not code-related #### Beta (Verbose Logger) - **Contribution**: Created comprehensive verbose logging for workflow - **Added**: Platform-specific timeouts, full output capture, JSON extraction - **Ready**: Enhanced workflow available but not needed after native runners worked #### Gamma (ARM64 Specialist) - **ROOT CAUSE FOUND**: QEMU emulation causes 10-22x slowdown - **Critical Discovery**: GitHub now provides FREE native ARM64 runners (ubuntu-24.04-arm) - **Evidence**: Other projects see 33 minutes (QEMU) vs 1m 26s (native) #### Zeta (Native ARM64 Implementation) - **Solution Applied**: Switched to native ARM64 runners - **Result**: ARM64 tests now complete in 2m 39s (was timing out at 7+ minutes) ## The Solution That Worked ### Changed Matrix Strategy in `.github/workflows/docker-testing.yml`: ```yaml strategy: fail-fast: false matrix: include: - platform: linux/amd64 runner: ubuntu-latest - platform: linux/arm64 runner: ubuntu-24.04-arm # Native ARM64! jobs: docker-build-test: runs-on: ${{ matrix.runner }} # Dynamic runner selection ``` ### Key Changes: 1. **Native ARM64 runners** eliminate QEMU completely 2. **QEMU setup** only for AMD64 builds (if: matrix.platform == 'linux/amd64') 3. **Reduced timeouts** from 15s to 10s for ARM64 (no emulation overhead) ## Docker Verification Strategy ### Initial Concern Tests were passing but we had no evidence the MCP server was actually returning API responses. Tests ran suspiciously fast (1m36s) suggesting cached builds. ### Simple Solution (User's Brilliant Idea) Instead of trying to bust Docker cache, just add logging to the actual code! #### Added to `src/index.ts`: ```typescript // In run() method: logger.info("BUILD VERIFICATION: Running build from 2025-08-17 16:30 UTC - PR606 ARM64 fix"); // In constructor: version: "1.0.0-build-20250817-1630-pr606" ``` ### Result: - Docker HAD to rebuild (source changed = cache invalidated) - Logs showed our BUILD VERIFICATION message - MCP server returned our custom version string - Proved definitively that Docker containers work ## Actual MCP Server Response Captured ```json { "result": { "protocolVersion": "2025-06-18", "capabilities": {"tools": {}}, "serverInfo": { "name": "dollhousemcp", "version": "1.0.0-build-20250817-1630-pr606" } }, "jsonrpc": "2.0", "id": 1 } ``` ## Lessons Learned ### What Worked 1. **Multi-agent investigation** - Parallel analysis identified root cause quickly 2. **Native ARM64 runners** - Complete solution, not a workaround 3. **Simple code changes** - Better than complex Docker cache busting 4. **Coordination document** - Central tracking for all agents ### What Didn't Work 1. **Cache busting** - Actually broke builds (removed in PR #611) 2. **Extended timeouts alone** - Just masks the QEMU problem 3. **Complex grep patterns** - MCP puts jsonrpc at END of response, not beginning ### Key Insights 1. **QEMU is the enemy** - 10-22x slowdown for CPU-intensive tasks like TypeScript compilation 2. **Native runners are available** - GitHub provides ubuntu-24.04-arm FREE for public repos 3. **Simple solutions are best** - Adding a log message proved more effective than complex cache strategies 4. **Trust but verify** - Always get concrete evidence of API responses ## Current Status ### All Tests Passing ✅ - Docker Build & Test (linux/amd64): ✅ PASS (1m 49s) - Docker Build & Test (linux/arm64): ✅ PASS (2m 2s) - No more timeouts! - Docker Compose Test: ✅ PASS - All other tests: ✅ PASS ### Evidence of Success - BUILD VERIFICATION message appears in logs - Custom version string in API response - Valid JSON-RPC responses confirmed - Response times excellent (5 seconds for full test) ## Files Modified 1. `.github/workflows/docker-testing.yml` - Native ARM64 runner configuration - Enhanced verbose logging (for future debugging) 2. `src/index.ts` - BUILD VERIFICATION log message - Custom version string with build identifier 3. Documentation created: - `/docs/development/DOCKER_ARM64_FIX_COORDINATION.md` - Multi-agent investigation - `/docs/development/SESSION_PR606_DOCKER_FIXES_FROM_611.md` - Initial analysis - `/docs/development/SESSION_PR606_ARM64_DOCKER_SUCCESS.md` - This summary ## Recommendations for Next Steps ### Immediate 1. **Merge PR #606** - All tests passing, Docker verified working 2. **Remove temporary build verification** - Clean up the test logging we added 3. **Keep native ARM64 runners** - Permanent solution ### Future Improvements 1. **Add permanent build info endpoint** - Include git SHA, build time in server info 2. **Fix grep patterns** - Update to handle jsonrpc at end of response 3. **Consider verbose logging toggle** - Keep Beta's enhancements but make optional 4. **Document native runner availability** - Update contributing guide ### For Similar Issues 1. **Check for CI-specific problems** - If works locally, investigate CI environment 2. **Look for native runners** - Avoid emulation when possible 3. **Use simple verification** - Change code to prove rebuilds rather than fight cache 4. **Multi-agent approach works** - Parallel investigation saves time ## Quick Reference for Future ### If Docker Tests Timeout on ARM64: ```yaml # Use native ARM64 runners: - platform: linux/arm64 runner: ubuntu-24.04-arm # Not ubuntu-latest! ``` ### To Verify Docker Builds Fresh: ```typescript // Add temporary log with timestamp: logger.info(`BUILD VERIFICATION: ${new Date().toISOString()}`); ``` ### To Check MCP Responses: Look for this in logs: - `"serverInfo":{"name":"dollhousemcp"` - `"jsonrpc":"2.0"` - Valid JSON-RPC structure ## Final Notes This was an excellent demonstration of: - Systematic debugging with multi-agent orchestration - Finding root causes rather than applying bandaids - The value of simple solutions over complex workarounds - The importance of verifying assumptions with evidence The ARM64 Docker issue that blocked us for a month is now completely resolved with a permanent, elegant solution. --- *Session completed successfully with all objectives achieved. PR #606 is ready to merge.*