Build System Maintenance

Shane McIntosh
Queen's University, Canada

The build system, i.e., the infrastructure that converts source code into deliverables, plays a critical role in the development of a software project. For example, developers rely upon the build system to test and run their source code changes. Without a working build system, development progress grinds to a halt, as the source code is rendered useless. Based on experiences reported by developers, we conjecture that build maintenance for large software systems is considerable, yet this maintenance is not well understood. A firm understanding of build maintenance is essential for project managers to allocate personnel and resources to build maintenance tasks effectively, and reduce the build maintenance overhead on regular development tasks, such as fixing defects and adding new features. In our work, we empirically study build maintenance in one proprietary and nine open source projects of different sizes and domain. Our case studies thus far show that: (1) similar to Lehman's first law of software evolution, build system specifications tend to grow unless effort is invested into restructuring them, (2) the build system accounts for up to 31% of the code files in a project, and (3) up to 27% of development tasks that change the source code also require build maintenance. Currently, we are working on identifying concrete measures that projects can take to reduce the build maintenance overhead.