AI coding agents have been increasingly integrated into software development workflows to help developers with various coding tasks. However, their effectiveness in real bug-fixing tasks remains uncertain. In this paper, we report on an analysis of 9,052 pull requests (PRs) from five agents—Codex, Copilot, Cursor, Claude, and Devin—alongside human-authored PRs from the same projects. We found that agentic PRs have lower acceptance rates than human-authored PRs (71.37% vs. 87.62%), although substantial variation exists between agents. To understand the reasons behind the rejection of agentic PRs, we manually examined 201 rejected agentic PRs and derived five categories of rejection factors. The most frequent issues are related to code quality, solution suitability, and failure to address reviewer feedback, often leading maintainers to abandon the review process. In many cases, agentic PRs are also superseded by other PRs. These findings shed light on current limitations of AI agents and highlight key challenges in developing more reliable and context-aware automated contributors.

Continuous Integration (CI) implies that a whole developer team works together on the mainline of a software project. CI systems automate the builds of a software. Sometimes a developer checks in code, which breaks the build. A broken build might not be a problem by itself, but it has the potential to disrupt co-workers, hence it affects the performance of the team. In this study, we investigate the interplay between non-functional requirements (NFRs) and builds statuses from 1,283 software projects. We found significant differences among NFRs related-builds statuses. Thus, tools can be proposed to improve CI with focus on new ways to prevent failures into CI, specially for efficiency and usability related builds. Also, the time required to put a broken build back on track indicates a bimodal distribution along all NFRs, with higher peaks within a day and lower peaks in six weeks. Our results suggest that more planned schedule for maintainability for Ruby, and for functionality and reliability for Java would decrease delays related to broken builds.