Git 2.56 Adds Safer Conflict Staging and Bulk Branch Cleanup, and Speeds Up Merge-Base Lookups on Large Repositories

Overview

The Git project released Git 2.56.0 on September 28, 2026. According to LWN.net, the release contains 748 non-merge commits made since Git 2.55 shipped in June, from 104 developers, 39 of them first-time contributors. New workflow commands include a safer way to stage resolved merge conflicts and a bulk command for deleting merged local branches, while a change to the merge-base search stopping rule accounts for the largest performance gains. The release follows the release candidate that The Machine Herald previously reported.

What Shipped

Staging only resolved conflicts

The new git add --resolved mode targets a specific mistake. As The GitHub Blog explains, git add -u updates every modified tracked path, which during a merge may include local changes unrelated to the conflict. The new mode considers only paths that are currently unmerged in the index. Before staging anything, per the same post, it scans unmerged regular files for leftover conflict markers; if it finds one, it reports the affected paths and leaves the index unchanged. The post adds that --resolved cannot be combined with -u or -A, and that it ignores tracked files that were never conflicted. Linuxiac describes the option as staging files after merge conflicts are fixed while avoiding unrelated changes in the working tree.

Bulk branch cleanup

According to The GitHub Blog, git branch --delete-merged deletes only local branches whose tips are reachable from their matching upstreams. It accepts patterns, such as origin/* to match upstreams and topic-* to limit local branch names, and a --dry-run flag lists what would be deleted without deleting anything. Branches checked out in a worktree, branches with missing upstreams and several ambiguous push configurations are skipped, and setting branch.<name>.deleteMerged = false protects a branch from bulk cleanup.

Faster merge-base searches

The blog post says Git 2.56 tracks how many queued commits remain painted exclusively by each side of a merge-base search, allowing the walk to stop earlier while still returning every merge base. In one real monorepo case, the traversal fell from 0.68 seconds to 0.01 seconds, according to The GitHub Blog. The same post reports that production evaluations on two large monorepos found many cases around 70 times faster in one and an average improvement around 20 times in the other. With the default v2 commit-graph, git merge-base --all v4.8 v4.9 on the Linux kernel fell from 167,441 traversal steps and 0.29 seconds to 3,887 steps and 0.01 seconds, per the same post.

Path-walk repacking and other scaling fixes

Path-walk repacking, which groups delta candidates by their location in the tree, previously could not be combined with reachability bitmaps or delta islands. The GitHub Blog reports that Git 2.56 removes both restrictions. In a benchmark on a recent clone of the Fluent UI repository, an ordinary bitmapped repack produced a 558.5 MB pack, while --path-walk produced a 164.4 MB pack, about 71% smaller. The post states that the changes do not enable path-walk repacking by default.

The post also lists internal scaling fixes. On a Chromium checkout with roughly 500,000 index entries, one affected git diff improved from about eight minutes to 0.07 seconds, and a prompt-related command that took 4.5 seconds in a repository with 37,815 packs no longer hits an O(N²) regression.

Other Additions

• git history drop <commit>: According to The GitHub Blog, the experimental command removes the selected commit and replays its descendants onto the commit’s parent. It cannot operate on a history that contains merge commits and cannot drop a root or merge commit. It follows reword and split in Git 2.54 and fixup in Git 2.55.
• git refs: The same post says the toolbox now supports create, update, delete and rename. git refs rename moves the ref and its reflog but does not perform the branch configuration adjustments that git branch -m does.
• git bisect run --reset-when-found: Per The GitHub Blog, the option combines finishing a bisection with resetting; by default it returns to the commit checked out before the bisection began.
• git replay --linearize: The experimental command can replay commits in a single line and drop merge commits without using the working tree, according to the same post.
• Command-line slip suggestions: Running git push origin/main now advises git push origin main, per the post.
• Partial clones: git repack -a --filter=blob:limit=1m --drop-filtered discards large, recoverable blobs so a later access fetches them again. The post says it currently supports only blob:limit filters and was contributed as a GSoC project by Siddharth Shrimali.

What We Don’t Know

The sources do not say when distributions or hosting providers will ship Git 2.56, or whether path-walk repacking will become a default. The monorepo speedups come from GitHub’s own evaluations, as reported in its post, and the sources do not identify the two monorepos or provide independent benchmarks. The 0.29-second-to-0.01-second figure applies to one Linux kernel command with the default v2 commit-graph, and results on other repositories will vary.