Week 2 of the GSoC 2025 coding period has arrived! Building upon the foundation established in Week 1, this week focused on deepening our migration expertise and tackling more complex technical challenges. With the development environment now properly configured and initial migration patterns established, we could shift our attention to refining the migration process and expanding our scope to additional models and scenarios.

This week brought significant progress in resolving technical issues encountered during Week 1, along with new insights into the intricacies of Gazebo migration work. Let me share the developments, solutions implemented, and lessons learned throughout this productive week!

Preliminaries

Following Week 1’s dual-Gazebo setup, repository recovery, and initial model migration, we began Week 2 by reviewing our environment and migration patterns in a mentor meeting. With basic compatibility secured, we shifted focus to systematic testing, issue resolution, and building robust workflows for Classic→Harmonic migrations.

Objectives

  • Correct apt repository error. Set up local environment: world launcher for gz-classic and gz-harmonic
  • Study FollowLine migration progress (https://github.com/pariaspe/ros_follow_line)
  • Complete Ackermann car model migration

Execution

System Recovery and Environment Setup

The week began with an unexpected but critical system administration challenge. I encountered a corrupted sudo apt repository on my development machine that prevented the installation of any new packages. This issue required immediate attention as it blocked all subsequent development work.

Repository Fix Process:

  • Diagnosed the corrupted repository sources
  • Cleaned and rebuilt the apt package cache
  • Restored proper repository configurations
  • Verified system package management functionality

Once the system was restored, I proceeded with the dual Gazebo installation setup.

Dual Gazebo Environment Configuration

Setting up both Gazebo Classic and Gazebo Harmonic simultaneously proved to be a complex but essential task. This configuration allows for comparative testing and ensures smooth migration workflows.

Installation Components:

  • Gazebo Classic (version 11) - for legacy support and comparison testing
  • Gazebo Harmonic - target platform for migration
  • ROS2 Humble integration with both versions
  • Environment variable management for seamless version switching

Key Configuration Steps:

# Gazebo Classic setup
sudo apt install gazebo11 gazebo11-dev

# Gazebo Harmonic setup
sudo apt install gz-harmonic

# Environment switching scripts
export GAZEBO_VERSION=classic  # or harmonic

The dual setup required careful management of:

  • Plugin library paths
  • Shared library conflicts
  • Environment variable isolation
  • Launch file compatibility

ROS Follow Line Repository Setup

I successfully cloned and configured the ros_follow_line repository to serve as a testing ground for migration work. This repository contains partially migrated components that provide valuable insights into the migration process.

Repository Analysis:

  • Examined existing migration patterns
  • Identified completed vs. pending migration tasks
  • Analyzed plugin migration approaches

The repository structure revealed important migration patterns:

  • Topic remapping strategies
  • Launch file modernization

F1 Ackermann Car Model Migration

The most significant technical achievement this week was successfully converting the F1 Ackermann car model from Gazebo Classic to Gazebo Harmonic compatibility.

Migration Components:

1. SDF Format Conversion

  • Modernized contact and friction elements
  • Removed deprecated physics parameters

2. Plugin System Overhaul

  • Replaced libgazebo_ros_ackermann_drive.so with gz-sim-ackermann-steering-system
  • added Gazebo Harmonic’s AckermannSteering system

Challenges and Issues

Repository Corruption Resolution

The week started with a significant setback when the apt repository became corrupted. This taught me the importance of:

  • Regular system backups
  • Understanding package management internals
  • Having recovery procedures documented

Gazebo Version Conflicts

Managing two Gazebo versions simultaneously presented several challenges:

  • Plugin library path conflicts
  • Environment variable interference
  • Launch file compatibility issues
  • Shared library version mismatches

Resolution Strategies:

  • Created isolated environment scripts
  • Implemented proper path management
  • Developed version-specific launch configurations

Migration Complexity

The F1 model migration revealed the depth of changes required:

  • Extensive plugin architecture differences
  • Complex controller configuration requirements
  • Topic and service name changes
  • Physics engine parameter updates

Next Steps

Looking ahead to Week 2, the priorities include:

1. Testing and Validation

  • Comprehensive testing of the migrated F1 model
  • Performance comparison between Classic and Harmonic

2. Documentation Creation

  • Migration guide documentation
  • Best practices documentation
  • Troubleshooting guides

Infrastructure Insights

My study of the Robotics Infrastructure repository revealed important structural patterns:

Organizational Principles:

  • Modular Architecture: Clear separation between worlds, models, and configurations
  • Version Management: Existing provisions for handling multiple Gazebo versions
  • Documentation Standards: Consistent documentation patterns across projects
  • Testing Framework: Basic infrastructure that can be expanded for migration validation

Migration Patterns Identified:

  • SDF version progression strategies
  • Plugin migration methodologies
  • Launch file modernization approaches
  • Controller configuration best practices

Reflection

This first week of coding has been both challenging and rewarding. The unexpected system issues at the beginning taught me the importance of robust development environment management. However, overcoming these challenges led to a more resilient and well-configured development setup.

The successful migration of the F1 Ackermann car model represents a significant milestone. The process revealed the complexity of migration work but also demonstrated that systematic approaches can handle these challenges effectively. The dual Gazebo environment setup provides an excellent foundation for comparative testing and validation.

Key Learnings:

  • Migration requires careful attention to plugin architecture changes
  • Environment management is crucial for multi-version development
  • Systematic testing approaches prevent regression issues
  • Documentation during migration saves significant time later

The foundation established this week positions us well for accelerated progress in subsequent weeks. With the environment properly configured and initial migration patterns established, we can focus on expanding the migration scope and developing comprehensive testing strategies.

I'm excited to continue building on this foundation and look forward to completing more complex migration scenarios in the coming weeks!