Provides clear handoff infos for continuing migration work with resolution strategies

qt6-after/qt6-migrated-legatus/BUILD_RTI_VALIDATION_REPORT.md

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+# BUILD_RTI=ON Validation Report
+
+## Executive Summary
+
+The Lts/DDS module has been successfully migrated to Qt6 with RTI Connext DDS 7.7 integration enabled (`BUILD_RTI=ON`). All core DDS targets compile and link successfully in the Docker build environment.
+
+**Date:** 2026-09-06  
+**Build Environment:** Ubuntu 26.04, Qt 6.10.2, RTI Connext DDS 7.7  
+**C++ Standard:** C++17 (required for RTI 7.7 compatibility)
+
+---
+
+## Build Results
+
+### Successfully Built Targets
+
+| Target | Library | Size | Status |
+|--------|---------|------|--------|
+| ddscore | libddscore.so | 4.3M | ✅ |
+| ddsftccore | libddsftccore.so | 550K | ✅ |
+| ddsQoS | libddsQoS.so | 1.6M | ✅ |
+| ddsconnector | libddsconnector.so | 4.4M | ✅ |
+| ddsgen | libddsgen.so | 3.1M | ✅ |
+
+### Build Configuration
+
+```bash
+# Docker image
+legatus-qt6-build:latest
+
+# CMake configuration
+cmake -DBUILD_RTI=ON -DCMAKE_CXX_STANDARD=17 ..
+
+# RTI License
+/home/torsten/swy/sandbox/rti_license.dat (empty development license)
+```
+
+---
+
+## Issues Resolved
+
+### 1. Qt5 API Deprecations (Qt6 Migration)
+
+**Problem:** `QByteArray::number()` is deprecated/removed in Qt6
+
+**Solution:** Replace with `QString::number(value).toLatin1()`
+
+**Files Modified:**
+- `Lts/DDS/FTC/generic_ftc_impl.h` (2 occurrences)
+- `Lts/DDS/FTS/connext.h` (1 occurrence)
+- `Lts/DDS/Routing/routing_plugin.h` (1 occurrence)
+- `Lts/DDS/Generic/generic_data_reader.h` (1 occurrence)
+
+### 2. C++ Standard Compatibility
+
+**Problem:** RTI 7.7 requires C++17, not C++23
+
+**Solution:** Changed `CMAKE_CXX_STANDARD` from 23 to 17 in parent CMakeLists.txt (line 99)
+
+### 3. AUTOMOC vs Codegen Timing
+
+**Problem:** AUTOMOC runs at configure time, but codegen macros run at build time. Generated files like `core_dtc.h` don't exist when moc tries to process them.
+
+**Solution:** 
+```cmake
+# Skip AUTOMOC for generated files
+set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/core_dtc.h SKIP_AUTOMOC ON)
+
+# Manually invoke QT6_WRAP_CPP with proper dependencies
+qt6_wrap_cpp(NGLEXTRA_SOURCES ${CMAKE_CURRENT_BINARY_DIR}/core_dtc.h
+    OPTIONS -I${CMAKE_SOURCE_DIR}/include -I${CMAKE_SOURCE_DIR}/Lts)
+```
+
+### 4. RTI Library Path Resolution
+
+**Problem:** RTI libraries exist on host at `/home/torsten/swy/sandbox/external/rti_connext_dds-7.7.0/lib/x64Linux4gcc8.5.0/` but must be mounted to `/workspace/external/rti_connext_dds-7.7.0` in container.
+
+**Solution:** Updated `cmake/FindRTI.cmake` to search `${CMAKE_SOURCE_DIR}/../../../external/` path
+
+### 5. PartitionType Enum Conversion
+
+**Problem:** Both `LtsSession::PartitionType` and `IDL::PartitionType` exist with different naming conventions (SCREAMING_SNAKE_CASE vs PascalCase)
+
+**Solution:** Added conversion functions in `lts_session_data_dds.h/.cpp`:
+```cpp
+IDL::PartitionType toIdlPartitionType(PartitionType type);
+PartitionType toPartitionType(IDL::PartitionType type);
+```
+
+### 6. Missing Fetcher Class
+
+**Problem:** Legacy version has `Fetcher` inline helper class and `m_guiPluginInterfaces` member that were missing from migrated version.
+
+**Solution:** Added to `lts_session_data_dds.h`:
+- `m_guiPluginInterfaces` member variable
+- `getForeignGuiInterface<S>()` template method
+- `Fetcher` class inline definition
+
+### 7. Missing generic_dtc_impl.h
+
+**Problem:** File was missing from migrated version's `include/DDS/DTC/` directory, causing incomplete type errors.
+
+**Solution:** Copied from legacy version to migrated version.
+
+### 8. RTI Header Conflicts
+
+**Problem:** `generic_dtc.h` had stub definitions for `LoanedSamples` and `SampleInfo` that conflicted with RTI's actual headers.
+
+**Solution:** Added conditional compilation guards:
+```cpp
+#ifdef BUILD_RTI
+    #include <dds/sub/LoanedSamples.hpp>
+    #include <dds/sub/SampleInfo.hpp>
+#else
+    // Stub definitions for BUILD_RTI=OFF
+#endif
+```
+
+### 9. DataModification Enum Conflict
+
+**Problem:** Stub enum in `generic_dtc.h` (Added, Modified, Removed) conflicted with `LtsUtilsCore/data_modification_enum.h` (eAdded, eModified, eRemoved).
+
+**Solution:** Only define stub enum when `BUILD_RTI=OFF`.
+
+---
+
+## File Changes Summary
+
+| File | Change Type | Description |
+|------|-------------|-------------|
+| `CMakeLists.txt` | Modified | C++17 standard, RTI path resolution |
+| `cmake/FindRTI.cmake` | Modified | Added external/ directory search path |
+| `Lts/DDS/Core/CMakeLists.txt` | Modified | AUTOMOC skip, manual QT6_WRAP_CPP |
+| `Lts/DDS/QosProfile/CMakeLists.txt` | Modified | Fixed include path |
+| `Lts/DDS/DDSConnector/CMakeLists.txt` | Modified | INTERFACE to PUBLIC include |
+| `Lts/Common/LtsSession/CMakeLists.txt` | Modified | Added ddsQoS link, fixed include path |
+| `Lts/Common/LtsSession/lts_session_data_dds.h` | Modified | Added members, Fetcher class, conversion functions |
+| `Lts/Common/LtsSession/lts_session_data_dds.cpp` | Modified | Implemented conversion functions |
+| `Lts/DDS/FTC/generic_ftc_impl.h` | Modified | Qt5 API fixes |
+| `Lts/DDS/FTS/connext.h` | Modified | Qt5 API fix |
+| `Lts/DDS/Routing/routing_plugin.h` | Modified | Qt5 API fix |
+| `Lts/DDS/Generic/generic_data_reader.h` | Modified | Qt5 API fix |
+| `include/DDS/Core/core.hpp` | Renamed | → core.hpp.stub (was blocking generated file) |
+| `include/DDS/Core/core_dtc_types.h` | Renamed | → core_dtc_types.h.stub (was blocking generated files) |
+| `include/DDS/DTC/generic_dtc_impl.h` | Added | Copied from legacy |
+| `include/DDS/DTC/generic_dtc.h` | Modified | Conditional RTI headers, enum fix |
+| `rti_license.dat` | Created | Empty development license |
+
+---
+
+## Known Issues (Out of Scope)
+
+### 1. ddsfts Build Failure
+
+**Status:** ❌ Not Built  
+**Cause:** Missing `pdm.idl` from ProjectDataManagement module
+
+**Details:**
+The `ddsfts` target depends on IDL files from the ProjectDataManagement module which is not part of the DDS migration scope. The build fails with:
+```
+File pdm.idl not found
+```
+
+**Resolution Path:**
+- Requires ProjectDataManagement module to be migrated first
+- Or create stub pdm.idl for build purposes only
+
+### 2. ProjectDataManagement Module
+
+**Location:** 
+- `Lts/Plugins/ProjectDataManagement/`
+- `Lts/Services/ProjectDataManagement/`
+
+**Status:** Not migrated  
+**Dependencies:** Required by ddsfts and other Project-related plugins
+
+**Known Issues:**
+- pdm.idl not available for DDS codegen
+- Potential Qt5 API usage (unverified)
+- CMake configuration not updated for Qt6
+
+### 3. Project Plugin Qt6 Migration Issues
+
+**Affected Plugins:**
+- ProjectEtsPlugin
+- ProjectAhtcPlugin
+- ProjectPluginBase
+- Other Project* plugins
+
+**Error Type:** `moc "Undefined interface"` errors  
+**Status:** Pre-existing issues, unrelated to DDS/RTI migration
+
+---
+
+## Validation Checklist
+
+- [x] RTI license file created and accessible
+- [x] RTI libraries mounted and discoverable by CMake
+- [x] C++17 standard enforced
+- [x] Qt5 API deprecations resolved
+- [x] Code generation runs during build (verified via nddsgen warnings in output)
+- [x] No stub/placeholder files for generated code
+- [x] ddscore builds successfully
+- [x] ddsftccore builds successfully
+- [x] ddsQoS builds successfully
+- [x] ddsconnector builds successfully
+- [x] ddsgen builds successfully
+- [ ] ddsfts builds (blocked by pdm.idl)
+- [ ] ProjectDataManagement migrated (out of scope)
+- [ ] Project plugins Qt6 migration (out of scope)
+
+---
+
+## Recommendations
+
+1. **For ddsfts:** Coordinate with ProjectDataManagement team to migrate pdm.idl or create temporary stub
+2. **For Project Plugins:** Address Qt6 migration issues in parallel workstream
+3. **For Future RTI Updates:** Document RTI version compatibility matrix (RTI 7.7 → C++17)
+4. **For Codegen:** Consider caching generated files to speed up clean builds
+
+---
+
+## Contact
+
+For questions about this migration, refer to:
+- Migration prompt: `./prompts/combined-migration-subfolder-dds-rti-compact.prompt.md`
+- Build documentation: `./app/Dockerfile`
+- RTI configuration: `./cmake/FindRTI.cmake`

qt6-after/qt6-migrated-legatus/DDS_RTI_MIGRATION_CONTINUATION_PROMPT.md

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+# DDS/RTI Migration - Continuation Prompt
+
+## Context
+
+This prompt continues the Qt6 migration work for the Lts/DDS module with RTI Connext DDS 7.7 integration. The core DDS targets (ddscore, ddsftccore, ddsQoS, ddsconnector, ddsgen) have been successfully migrated and build with `BUILD_RTI=ON`.
+
+## Completed Work
+
+See `BUILD_RTI_VALIDATION_REPORT.md` for detailed results of completed migration work.
+
+## Remaining Tasks
+
+### Priority 1: ddsfts Module
+
+**Location:** `Lts/DDS/FTS/`
+
+**Blocker:** Missing `pdm.idl` from ProjectDataManagement module
+
+**Required Actions:**
+1. Check if `pdm.idl` exists in legacy Qt5 version
+2. If exists, copy to migrated version's IDL directory
+3. Verify CMakeLists.txt references correct IDL path
+4. If pdm.idl doesn't exist, create minimal stub for build purposes:
+   ```idl
+   module ProjectDataManagement {
+       // Stub IDL for build purposes
+       struct ProjectData {
+           string id;
+       };
+   };
+   ```
+5. Rebuild ddsfts target
+6. Verify no additional RTI header conflicts
+
+**Files to Check:**
+- `qt-migration-legatus/qt5-before/qt5-legatus-legacy/Lts/DDS/FTS/` (legacy)
+- `qt-migration-legatus/qt6-after/qt6-migrated-legatus/Lts/DDS/FTS/` (migrated)
+- `Lts/Plugins/ProjectDataManagement/` (source of pdm.idl)
+- `Lts/Services/ProjectDataManagement/` (source of pdm.idl)
+
+### Priority 2: ProjectDataManagement Module Migration
+
+**Locations:**
+- `Lts/Plugins/ProjectDataManagement/`
+- `Lts/Services/ProjectDataManagement/`
+
+**Migration Checklist:**
+- [ ] Inventory all Qt5 API usage (QByteArray::number, deprecated signals/slots, etc.)
+- [ ] Update CMakeLists.txt for Qt6 (find_package(Qt6 COMPONENTS ...))
+- [ ] Verify KTextTemplate configuration for any IDL codegen
+- [ ] Check for AUTOMOC timing issues with generated files
+- [ ] Update include paths if necessary
+- [ ] Build with BUILD_RTI=ON to verify compatibility
+- [ ] Run any existing tests
+
+**Qt5 API Patterns to Search:**
+```bash
+# In ProjectDataManagement directories
+grep -r "QByteArray::number" --include="*.h" --include="*.cpp"
+grep -r "QRegExp" --include="*.h" --include="*.cpp"
+grep -r "QDesktopWidget" --include="*.h" --include="*.cpp"
+grep -r "QApplication::desktop" --include="*.h" --include="*.cpp"
+```
+
+**CMake Updates Needed:**
+```cmake
+# Qt5 pattern (legacy)
+find_package(Qt5 REQUIRED COMPONENTS Core Widgets)
+
+# Qt6 pattern (migrated)
+find_package(Qt6 REQUIRED COMPONENTS Core Widgets)
+qt_standardize_properties()
+```
+
+### Priority 3: Project Plugin Qt6 Migration
+
+**Affected Plugins:**
+- `Lts/Plugins/ProjectEtsPlugin/`
+- `Lts/Plugins/ProjectAhtcPlugin/`
+- `Lts/Plugins/ProjectPluginBase/`
+- `Lts/Plugins/Project*Plugin/`
+
+**Known Error:** `moc "Undefined interface"` 
+
+**Investigation Steps:**
+1. Check Q_PLUGIN_METADATA declarations
+2. Verify interface classes have Q_DECLARE_INTERFACE
+3. Check for missing Q_OBJECT macros
+4. Verify AUTOMOC is enabled in CMakeLists.txt
+5. Check for circular dependencies between plugins
+
+**Common Qt6 Migration Issues:**
+- Q_PLUGIN_METADATA requires QJsonDocument in Qt6
+- Interface UUIDs must be consistent
+- Plugin loading may require Q_PLUGIN_IMPORT in addition to Q_PLUGIN_METADATA
+
+---
+
+## Build Commands
+
+### Standard DDS Build (Working)
+```bash
+docker run --rm -it \
+  -v /home/torsten/swy/sandbox:/workspace \
+  -v /home/torsten/swy/sandbox/rti_license.dat:/workspace/rti_license.dat:ro \
+  legatus-qt6-build:latest \
+  bash -c "cd /workspace/qt-migration-legatus/qt6-after/qt6-migrated-legatus && \
+           mkdir -p build && cd build && \
+           cmake -DBUILD_RTI=ON -DCMAKE_CXX_STANDARD=17 .. && \
+           make -j8 ddscore ddsftccore ddsQoS ddsconnector ddsgen"
+```
+
+### Full DDS Build (Including ddsfts)
+```bash
+docker run --rm -it \
+  -v /home/torsten/swy/sandbox:/workspace \
+  -v /home/torsten/swy/sandbox/rti_license.dat:/workspace/rti_license.dat:ro \
+  legatus-qt6-build:latest \
+  bash -c "cd /workspace/qt-migration-legatus/qt6-after/qt6-migrated-legatus && \
+           mkdir -p build && cd build && \
+           cmake -DBUILD_RTI=ON -DCMAKE_CXX_STANDARD=17 .. && \
+           make -j8 ddscore ddsftccore ddsQoS ddsconnector ddsgen ddsfts"
+```
+
+### ProjectDataManagement Build (After Migration)
+```bash
+docker run --rm -it \
+  -v /home/torsten/swy/sandbox:/workspace \
+  -v /home/torsten/swy/sandbox/rti_license.dat:/workspace/rti_license.dat:ro \
+  legatus-qt6-build:latest \
+  bash -c "cd /workspace/qt-migration-legatus/qt6-after/qt6-migrated-legatus && \
+           mkdir -p build && cd build && \
+           cmake -DBUILD_RTI=ON -DCMAKE_CXX_STANDARD=17 .. && \
+           make -j8 ProjectDataManagement"
+```
+
+---
+
+## Known Issues Reference
+
+### Issue: ddsfts Build Failure
+- **Severity:** High (blocks complete DDS module build)
+- **Root Cause:** Missing pdm.idl dependency
+- **Workaround:** Create stub pdm.idl or migrate ProjectDataManagement first
+- **Files Involved:** `Lts/DDS/FTS/CMakeLists.txt`, `Lts/Plugins/ProjectDataManagement/`
+
+### Issue: ProjectDataManagement Not Migrated
+- **Severity:** Medium (blocks ddsfts, affects Project plugins)
+- **Root Cause:** Not yet started in current migration wave
+- **Workaround:** None - requires full migration
+- **Files Involved:** `Lts/Plugins/ProjectDataManagement/`, `Lts/Services/ProjectDataManagement/`
+
+### Issue: Project Plugin moc Errors
+- **Severity:** Medium (affects plugin loading, not DDS core)
+- **Root Cause:** Qt6 plugin interface changes
+- **Workaround:** Build without plugins or fix Q_PLUGIN_METADATA declarations
+- **Files Involved:** `Lts/Plugins/Project*Plugin/`
+
+---
+
+## Testing Guidelines
+
+### After ddsfts Build
+1. Verify libddsfts.so is created
+2. Check for undefined symbols: `nm -D libddsfts.so | grep U`
+3. Test plugin loading if applicable
+
+### After ProjectDataManagement Migration
+1. Build ddsfts and verify success
+2. Run any ProjectDataManagement unit tests
+3. Verify pdm.idl codegen produces expected headers
+4. Test integration with DDS module
+
+### After Project Plugin Migration
+1. Build all Project*Plugin targets
+2. Verify plugins load at runtime
+3. Test plugin interfaces with host application
+4. Check for moc warnings in build output
+
+---
+
+## Success Criteria
+
+### ddsfts Module
+- [ ] ddsfts target builds without errors
+- [ ] libddsfts.so is created
+- [ ] No undefined symbol errors
+- [ ] pdm.idl codegen runs successfully
+
+### ProjectDataManagement Module
+- [ ] All Qt5 API usage replaced with Qt6 equivalents
+- [ ] CMakeLists.txt uses Qt6 find_package
+- [ ] Module builds with BUILD_RTI=ON
+- [ ] No moc warnings or errors
+- [ ] pdm.idl generates expected headers
+
+### Project Plugins
+- [ ] All Project*Plugin targets build
+- [ ] No "Undefined interface" moc errors
+- [ ] Plugins load successfully at runtime
+- [ ] Plugin interfaces work correctly
+
+---
+
+## Notes
+
+- RTI 7.7 requires C++17 (not C++23)
+- Empty rti_license.dat is valid for development
+- Code generation must happen during build (no pre-generated files)
+- AUTOMOC timing issues require SKIP_AUTOMOC + manual QT6_WRAP_CPP for generated files
+- RTI headers conflict with stub definitions - use #ifdef BUILD_RTI guards

qt6-after/qt6-migrated-legatus/KNOWN_ISSUES_DDSFTS_PROJECTDATAMANAGEMENT.md

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+# Known Issues - ddsfts and ProjectDataManagement
+
+## Overview
+
+This document tracks known issues blocking the complete migration of the DDS module, specifically the ddsfts target and its dependency on ProjectDataManagement.
+
+---
+
+## Issue #1: ddsfts Build Failure
+
+### Status
+❌ **Blocked** - Cannot build until pdm.idl is available
+
+### Error Message
+```
+File pdm.idl not found
+[Error from nddsgen codegen step]
+```
+
+### Root Cause
+The `ddsfts` target depends on IDL files from the ProjectDataManagement module. The file `pdm.idl` is not present in the migrated codebase because:
+1. ProjectDataManagement module has not been migrated yet
+2. The IDL file may not exist in the expected location
+3. CMake IDL search paths may not be configured correctly
+
+### Impact
+- ddsfts library cannot be built
+- Any code depending on ddsfts is blocked
+- Complete DDS module validation is incomplete
+
+### Location
+- **Target:** `Lts/DDS/FTS/CMakeLists.txt`
+- **Dependency:** `Lts/Plugins/ProjectDataManagement/` or `Lts/Services/ProjectDataManagement/`
+- **Missing File:** `pdm.idl`
+
+### Resolution Options
+
+#### Option A: Migrate ProjectDataManagement First (Recommended)
+1. Migrate ProjectDataManagement module to Qt6
+2. Ensure pdm.idl is in correct location
+3. Update ddsfts CMakeLists.txt to reference correct IDL path
+4. Rebuild ddsfts
+
+**Pros:** Proper long-term solution  
+**Cons:** Requires additional migration work
+
+#### Option B: Create Stub pdm.idl (Temporary)
+1. Create minimal pdm.idl stub in `include/DDS/FTS/` or similar
+2. Define only the types needed by ddsfts
+3. Document as temporary workaround
+4. Replace with real pdm.idl after ProjectDataManagement migration
+
+**Pros:** Unblocks ddsfts build quickly  
+**Cons:** May not match actual IDL, could cause runtime issues
+
+#### Option C: Exclude ddsfts from Build (Workaround)
+1. Wrap ddsfts in additional CMake conditional
+2. Build other DDS targets without ddsfts
+3. Document ddsfts as temporarily unavailable
+
+**Pros:** Allows other DDS targets to be used  
+**Cons:** Incomplete DDS module
+
+### Investigation Steps
+
+1. **Search for pdm.idl in legacy version:**
+   ```bash
+   find qt-migration-legatus/qt5-before -name "pdm.idl"
+   ```
+
+2. **Check ProjectDataManagement directories:**
+   ```bash
+   ls -la Lts/Plugins/ProjectDataManagement/
+   ls -la Lts/Services/ProjectDataManagement/
+   ```
+
+3. **Check ddsfts CMakeLists.txt for IDL references:**
+   ```bash
+   grep -n "pdm" Lts/DDS/FTS/CMakeLists.txt
+   grep -n "IDL" Lts/DDS/FTS/CMakeLists.txt
+   ```
+
+4. **Search for pdm references in code:**
+   ```bash
+   grep -r "pdm" Lts/DDS/FTS/ --include="*.h" --include="*.cpp"
+   ```
+
+---
+
+## Issue #2: ProjectDataManagement Module Not Migrated
+
+### Status
+⚠️ **Not Started** - Requires full Qt6 migration
+
+### Locations
+- `Lts/Plugins/ProjectDataManagement/`
+- `Lts/Services/ProjectDataManagement/`
+
+### Known Dependencies
+- ddsfts (blocks ddsfts build)
+- ProjectEtsPlugin (likely depends on ProjectDataManagement)
+- ProjectAhtcPlugin (likely depends on ProjectDataManagement)
+- Other Project* plugins
+
+### Migration Checklist
+
+#### Phase 1: Assessment
+- [ ] Inventory all source files (.h, .cpp)
+- [ ] Inventory all IDL files (.idl)
+- [ ] Review CMakeLists.txt structure
+- [ ] Identify Qt5 API usage
+- [ ] Identify code generation requirements
+
+#### Phase 2: Qt6 API Migration
+- [ ] Replace QByteArray::number() → QString::number().toLatin1()
+- [ ] Replace QRegExp → QRegularExpression
+- [ ] Replace QDesktopWidget → QScreen
+- [ ] Update signal/slot syntax if needed
+- [ ] Update any deprecated Qt classes
+
+#### Phase 3: CMake Configuration
+- [ ] Change find_package(Qt5...) to find_package(Qt6...)
+- [ ] Add qt_standardize_properties()
+- [ ] Configure KTextTemplate for IDL codegen
+- [ ] Fix include paths
+- [ ] Set CMAKE_CXX_STANDARD to 17
+
+#### Phase 4: RTI Integration
+- [ ] Verify BUILD_RTI compatibility
+- [ ] Check for RTI header conflicts
+- [ ] Test with BUILD_RTI=ON
+
+#### Phase 5: Validation
+- [ ] Build without errors
+- [ ] No moc warnings
+- [ ] Run unit tests if available
+- [ ] Verify IDL codegen output
+
+### Potential Issues
+
+#### Qt5 API Usage (Expected)
+Based on patterns in other modules, expect to find:
+- `QByteArray::number()` - Replace with `QString::number().toLatin1()`
+- `QRegExp` - Replace with `QRegularExpression`
+- `QApplication::desktop()` - Replace with `QGuiApplication::primaryScreen()`
+
+#### Code Generation
+- May use KTextTemplate for IDL → C++ generation
+- Check for AUTOMOC timing issues with generated files
+- May need SKIP_AUTOMOC + manual QT6_WRAP_CPP pattern
+
+#### Include Paths
+- Legacy paths may reference `LtsUtils/` instead of `Lts/`
+- Check all `#include` directives after migration
+
+---
+
+## Issue #3: Project Plugin Qt6 Migration Issues
+
+### Status
+⚠️ **Pre-existing Issues** - Unrelated to DDS/RTI migration
+
+### Affected Plugins
+- ProjectEtsPlugin
+- ProjectAhtcPlugin
+- ProjectPluginBase
+- Project*Plugin (other Project plugins)
+
+### Error Type
+```
+moc: Undefined interface
+```
+
+### Root Cause Analysis Needed
+1. Check Q_PLUGIN_METADATA declarations
+2. Verify Q_DECLARE_INTERFACE in interface classes
+3. Check for missing Q_OBJECT macros
+4. Verify AUTOMOC is enabled
+5. Check for circular dependencies
+
+### Investigation Commands
+```bash
+# Find all Project plugins
+find Lts/Plugins -name "*Project*Plugin" -type d
+
+# Check for Q_PLUGIN_METADATA
+grep -r "Q_PLUGIN_METADATA" Lts/Plugins/Project*Plugin/ --include="*.h"
+
+# Check for Q_DECLARE_INTERFACE
+grep -r "Q_DECLARE_INTERFACE" Lts/Plugins/Project*Plugin/ --include="*.h"
+
+# Check CMakeLists.txt for AUTOMOC
+grep -r "AUTOMOC" Lts/Plugins/Project*Plugin/CMakeLists.txt
+```
+
+### Common Qt6 Plugin Issues
+
+#### Issue: Q_PLUGIN_METADATA requires QJsonDocument
+**Qt5:**
+```cpp
+Q_PLUGIN_METADATA(IID "com.example.PluginInterface" FILE "plugin.json")
+```
+
+**Qt6:** May require additional QJsonDocument handling
+
+#### Issue: Interface UUID Changes
+Plugin interface UUIDs must be consistent between:
+- Q_DECLARE_INTERFACE declaration
+- Q_PLUGIN_METADATA IID string
+- Plugin loader expectations
+
+#### Issue: Plugin Loading
+Qt6 may require both Q_PLUGIN_METADATA and Q_PLUGIN_IMPORT for proper plugin loading.
+
+---
+
+## Resolution Priority
+
+| Priority | Issue | Impact | Effort | Recommendation |
+|----------|-------|--------|--------|----------------|
+| 1 | ddsfts missing pdm.idl | High (blocks DDS) | Low-Medium | Create stub or migrate ProjectDataManagement |
+| 2 | ProjectDataManagement migration | High (enables ddsfts) | High | Full migration required |
+| 3 | Project plugin moc errors | Medium (plugins only) | Medium | Fix after DDS module complete |
+
+---
+
+## Action Items
+
+### Immediate (Unblock ddsfts)
+- [ ] Search for pdm.idl in legacy codebase
+- [ ] If found, copy to migrated version
+- [ ] If not found, create minimal stub
+- [ ] Update ddsfts CMakeLists.txt if needed
+- [ ] Rebuild ddsfts
+
+### Short-term (Complete DDS module)
+- [ ] Migrate ProjectDataManagement module
+- [ ] Verify all DDS targets build with BUILD_RTI=ON
+- [ ] Document any remaining issues
+
+### Long-term (Complete Qt6 migration)
+- [ ] Migrate all Project* plugins
+- [ ] Fix moc "Undefined interface" errors
+- [ ] Verify plugin loading at runtime
+- [ ] Run full test suite
+
+---
+
+## References
+
+- BUILD_RTI Validation Report: `BUILD_RTI_VALIDATION_REPORT.md`
+- Migration Continuation Prompt: `DDS_RTI_MIGRATION_CONTINUATION_PROMPT.md`
+- Migration Instructions: `../prompts/combined-migration-subfolder-dds-rti-compact.prompt.md`
+- RTI Configuration: `../cmake/FindRTI.cmake`
+- Build Environment: `../app/Dockerfile`