Merge-Bench: Resolve Merge Conflicts with Large Language Models

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Schesch, Benedikt, Ernst, Michael D.
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918521568493568
author Schesch, Benedikt
Ernst, Michael D.
author_facet Schesch, Benedikt
Ernst, Michael D.
contents This paper applies machine learning to the difficult and important task of version control merging. (1) We constructed a dataset, Merge-Bench, of 7938 real-world merge conflict hunks from 1439 GitHub repositories. The ground truth is the merge resolution that developers committed to the repository. Our dataset construction methodology is scalable to arbitrary amounts of data since no manual labeling is required. (2) We trained a model, LLMergeJ, to resolve merge conflicts in Java programs. Our approach uses Group Relative Policy Optimization (GRPO), an online reinforcement learning method, to train a Large Language Model (LLM). (3) We performed two evaluations of the performance of LLMs on resolving merge conflicts. On Java programs, LLMergeJ with 14B parameters outperforms 3 commercial LLMs, trailing only Gemini 2.5 Pro. Across 11 programming languages, commercial LLM performance is largely stable from language to language. The best models correctly resolve less than 60% of merge conflicts.
format Preprint
id arxiv_https___arxiv_org_abs_2605_25890
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Merge-Bench: Resolve Merge Conflicts with Large Language Models
Schesch, Benedikt
Ernst, Michael D.
Machine Learning
I.2.7; D.2.7; I.2.6
This paper applies machine learning to the difficult and important task of version control merging. (1) We constructed a dataset, Merge-Bench, of 7938 real-world merge conflict hunks from 1439 GitHub repositories. The ground truth is the merge resolution that developers committed to the repository. Our dataset construction methodology is scalable to arbitrary amounts of data since no manual labeling is required. (2) We trained a model, LLMergeJ, to resolve merge conflicts in Java programs. Our approach uses Group Relative Policy Optimization (GRPO), an online reinforcement learning method, to train a Large Language Model (LLM). (3) We performed two evaluations of the performance of LLMs on resolving merge conflicts. On Java programs, LLMergeJ with 14B parameters outperforms 3 commercial LLMs, trailing only Gemini 2.5 Pro. Across 11 programming languages, commercial LLM performance is largely stable from language to language. The best models correctly resolve less than 60% of merge conflicts.
title Merge-Bench: Resolve Merge Conflicts with Large Language Models
topic Machine Learning
I.2.7; D.2.7; I.2.6
url https://arxiv.org/abs/2605.25890