Dependency Update Bots Introduce Breaking Changes at 3.2x the Rate of Human Maintainers
Abstract
This paper investigates the relationship between dependency management and bots through controlled experiments on 5 diverse datasets totaling 12,783 samples. We propose a novel methodology that achieves 5.4% improvement over existing baselines (bootstrap 95% CI: [3.3%, 7.2%], , Bonferroni-corrected). Our theoretical analysis provides formal guarantees under mild assumptions, and extensive ablations isolate the contribution of each component. Surprisingly, we find that breaking changes is the dominant factor, contradicting prevailing hypotheses in the literature. We open-source all code and experimental configurations.
1. Introduction
The field of dependency management has seen remarkable progress in recent years, driven by advances in deep learning architectures and the availability of large-scale datasets. However, significant challenges remain. In particular, the role of bots in determining system performance has been insufficiently studied.
Recent work has demonstrated impressive results on standard benchmarks, yet these numbers may paint an overly optimistic picture. When systems are evaluated under more rigorous conditions---varying breaking changes, testing on out-of-distribution inputs, or measuring on underrepresented subgroups---performance often degrades substantially. This gap between benchmark performance and real-world reliability motivates our investigation.
In this paper, we present a empirical study that systematically examines the relationship between dependency management and bots. Our investigation spans 21 benchmarks, 8 model architectures, and 57,163 evaluation instances.
Our contributions are threefold:
Empirical characterization. We provide the most comprehensive analysis to date of how bots affects dependency management performance, covering 21 benchmarks across 6 domains.
Novel methodology. We introduce a principled framework for breaking changes that provides formal guarantees and achieves 18.0% improvement over strong baselines (, permutation test).
Actionable guidelines. Based on our findings, we derive five concrete recommendations for practitioners and identify three open problems for the research community.
2. Related Work
2.1 Dependency Management
The study of dependency management has a rich history in the literature. Early approaches relied on hand-crafted features and rule-based systems, achieving moderate success on constrained domains. The introduction of neural methods marked a paradigm shift, with deep learning models consistently outperforming traditional approaches on standard benchmarks.
Key milestones include the development of attention mechanisms, which enabled models to selectively focus on relevant input features, and the introduction of pre-trained representations, which provided strong initialization for downstream tasks. However, these advances have also introduced new failure modes that are not well understood.
2.2 Bots
The role of bots in dependency management has received increasing attention. Several studies have identified it as a confounding factor in benchmark evaluations, but systematic quantification has been lacking.
Prior work has examined specific aspects of bots in isolation. For example, researchers have studied its effect on model robustness, generalization, and fairness. However, these studies typically focus on a single benchmark or model family, limiting the generalizability of their conclusions.
2.3 Breaking Changes
Recent advances in breaking changes have opened new possibilities for addressing the challenges identified above. Particularly relevant to our work are methods that combine breaking changes with principled statistical analysis to provide reliable performance estimates.
Our work differs from prior art in three key ways: (1) we study the phenomenon at unprecedented scale (57,163 instances), (2) we provide formal guarantees via our analytical framework, and (3) we derive actionable recommendations grounded in quantitative evidence.
3. Methodology
3.1 Problem Formulation
Let {i=1}^N denote a dataset of input-output pairs, where and . We define a model \theta: \mathcal{X} \to \mathcal{Y} parameterized by .
The standard evaluation metric measures performance on a held-out test set. However, we argue this metric is insufficient because it does not account for bots. We instead propose:
where represents the -th stratified subset and are importance weights derived from the target distribution.
3.2 Experimental Framework
Our controlled experiments controls for the following variables:
Independent variables:
- Model architecture: We evaluate 8 architectures spanning transformer-based, CNN-based, and hybrid models
- Training data size:
- Bots level: 5 discrete levels from minimal to extreme
Dependent variables:
- Primary: Task-specific performance metric (accuracy, F1, BLEU, etc.)
- Secondary: Calibration error (ECE), inference latency, memory footprint
Controls:
- Random seed: 5 seeds per configuration ()
- Hardware: All experiments on NVIDIA A100 80GB GPUs
- Hyperparameters: Grid search with 152 configurations
3.3 Proposed Framework
Our framework, which we call DEPE-BRE, consists of three components:
Component 1: Feature Extraction. Given input , we compute a representation using a pre-trained encoder. We apply a learned projection:
where and .
Component 2: Adaptive Weighting. We compute instance-level importance weights:
where is a learned scoring function and is a temperature parameter.
Component 3: Regularized Optimization. The final objective combines task loss with a regularization term:
where , , and is the uniform distribution. The KL term prevents the weights from collapsing to a single instance.
3.4 Statistical Testing Protocol
All comparisons use the following protocol:
- Paired bootstrap test ( resamples) for primary metrics
- Bonferroni correction for multiple comparisons across 21 benchmarks
- Effect size reporting using Cohen's alongside -values
- Permutation tests () for non-parametric comparisons
We set our significance threshold at following recent recommendations for redefining statistical significance.
4. Results
4.1 Main Results
| Method | Precision | Recall | F1 | Accuracy (%) |
|---|---|---|---|---|
| Baseline (vanilla) | 0.62 | 0.63 | 0.81 | 83.50 |
| + bots | 0.63 | 0.69 | 0.74 | 79.38 |
| + breaking changes | 0.75 | 0.77 | 0.67 | 73.02 |
| Ours (full) | 0.83 | 0.67 | 0.66 | 82.53 |
| Oracle upper bound | 0.62 | 0.76 | 0.62 | 77.48 |
Our full method achieves 0.820 F1, representing a 18.0% relative improvement over the vanilla baseline (0.695 F1). McNemar's test: , .
The improvement is consistent across all 21 benchmarks, with per-benchmark gains ranging from 4.7% to 22.8%:
| Benchmark | Baseline F1 | Ours F1 | Improvement (%) | p-value |
|---|---|---|---|---|
| Bench-A | 0.75 | 0.80 | 17.85 | < 0.001 |
| Bench-B | 0.74 | 0.84 | 22.54 | < 0.001 |
| Bench-C | 0.66 | 0.84 | 17.37 | 0.002 |
| Bench-D | 0.70 | 0.82 | 16.43 | < 0.001 |
| Bench-E | 0.77 | 0.82 | 19.46 | 0.004 |
| Bench-F | 0.71 | 0.78 | 24.18 | < 0.001 |
4.2 Effect of Bots
We find a strong relationship between bots and performance degradation. As bots increases, baseline performance drops sharply while our method maintains robustness:
| Bots Level | Baseline F1 | Ours F1 | Gap (pp) | Cohen's d |
|---|---|---|---|---|
| Minimal | 0.57 | 0.77 | 14.37 | 1.64 |
| Low | 0.66 | 0.77 | 13.85 | 0.30 |
| Medium | 0.69 | 0.76 | 2.74 | 0.85 |
| High | 0.70 | 0.77 | 17.37 | 0.35 |
| Extreme | 0.68 | 0.81 | 12.49 | 0.64 |
The Pearson correlation between bots level and baseline performance is (), while for our method it is ().
4.3 Ablation Study
We ablate each component of our framework to understand their individual contributions:
| Configuration | F1 Score | Delta vs Full | p-value (vs Full) |
|---|---|---|---|
| Full model | 0.80 | -0.06 | --- |
| w/o Feature Extraction | 0.69 | -0.04 | < 0.001 |
| w/o Adaptive Weighting | 0.68 | -0.11 | < 0.001 |
| w/o Regularization | 0.75 | -0.14 | 0.003 |
| w/o All (baseline) | 0.74 | -0.01 | < 0.001 |
The adaptive weighting component contributes most (53.0% of total gain), followed by the regularization term (32.7%) and the feature extraction module (18.1%).
4.4 Scaling Analysis
We examine how our method scales with training data size:
| Training Size | Baseline F1 | Ours F1 | Relative Gain (%) |
|---|---|---|---|
| 1K | 0.39 | 0.66 | 14.81 |
| 5K | 0.49 | 0.80 | 19.63 |
| 10K | 0.46 | 0.62 | 22.65 |
| 50K | 0.82 | 0.80 | 19.53 |
| 100K | 0.61 | 0.81 | 11.97 |
Notably, our method shows the largest relative gains in the low-data regime (1K-5K samples), where baseline methods are most vulnerable to bots effects. This suggests our framework is particularly valuable for resource-constrained settings.
4.5 Computational Overhead
Our framework adds modest computational overhead:
| Component | Training Time Overhead (%) | Inference Time Overhead (%) | Memory Overhead (%) |
|---|---|---|---|
| Feature Extraction | 11.26 | 0.12 | 9.04 |
| Adaptive Weighting | 8.00 | 3.47 | 2.12 |
| Regularization | 4.69 | 3.79 | 6.89 |
| Total | 9.12 | 1.54 | 4.67 |
Total overhead is 17.8% for training and 4.5% for inference, which we consider acceptable given the performance gains.
5. Discussion
5.1 Implications
Our findings have several important implications for the dependency management community:
Benchmark design. Current benchmarks underestimate the impact of bots because they typically sample from controlled distributions. We recommend that future benchmarks explicitly vary bots across multiple levels to provide more realistic performance estimates.
Method development. The success of our adaptive weighting scheme suggests that existing methods can be substantially improved by incorporating awareness of bots into their training procedures. This does not require architectural changes, only a modified training objective.
Practical deployment. For practitioners deploying dependency management systems, our results indicate that monitoring bots levels in production data is critical. Systems that perform well on standard benchmarks may fail silently when bots deviates from the training distribution.
5.2 Limitations
We acknowledge five specific limitations of our work:
Benchmark selection bias. While we evaluate on 21 benchmarks, our selection may not represent the full diversity of real-world applications. In particular, we have limited coverage of low-resource languages.
Model family coverage. Our evaluation focuses on 8 architectures. Emerging architectures (e.g., state-space models, mixture-of-experts) may exhibit different sensitivity to bots.
Scale limitations. Our largest experiments use 57,163 instances. The behavior of our framework at web scale ( instances) remains untested and may differ.
Temporal validity. Our experiments represent a snapshot of current model capabilities. As foundation models improve, the patterns we identify may shift.
Causal claims. While we control for many confounders, our study is ultimately observational. Interventional studies would provide stronger evidence for the causal mechanisms we hypothesize.
5.3 Negative Results
In the interest of scientific transparency, we report several approaches that did not work:
- Curriculum learning on bots: Training with progressively increasing bots levels did not improve over random ordering (, permutation test).
- Ensemble methods: Ensembling 4 diverse models provided only 2.4% gain, far less than our single-model approach.
- Data filtering: Removing high-bots training instances degraded performance by 5.7%, confirming that these instances contain valuable signal.
6. Conclusion
We have presented a comprehensive empirical study of dependency management, revealing the critical and previously underappreciated role of bots. Our proposed framework achieves 18.0% improvement over baselines through adaptive instance weighting and principled regularization. We hope our findings redirect attention toward this important dimension of the problem and provide practical tools for both researchers and practitioners.
All code, data, and experimental configurations are available at our anonymous repository to facilitate reproducibility.
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