git-lfs-git

Git interop helpers for Git LFS: config, refs, scanners, and .gitattributes matching.

Git LFS needs the user's git binary for a handful of things with no LFS-specific equivalent: where the repo lives, what's in its config, which objects each ref reaches, and how .gitattributes applies to a given path. This crate collects those helpers in one place. Everything runs by shelling out to the git binary the user has installed; this crate does not bundle its own git implementation.

It sits at the bottom of the LFS workspace: every other crate (api, transfer, creds, filter, store) goes through it whenever it needs to know something about the repo it's running against. The crate is intentionally a collection of unrelated helpers rather than a single abstraction, so the pieces are independent of each other; pick what you need.

This crate implements helpers related to:

• Path: locate .git/, the work tree, and .git/lfs/ for a path, including multi-worktree edge cases.
• Config: read and write Git configuration at local, global, system, and worktree scope, plus the .lfsconfig overlay and specific surfaces like http.<url>.* HTTP options, url.<base>.insteadOf URL aliases, lfs.extension.<name>.* pointer extensions, and the lfs.fetchrecent* and lfs.prune* windows.
• Endpoint: walk the full upstream priority chain (GIT_LFS_URL → lfs.url → remote.<name>.lfsurl → derived from remote.<name>.url, with SSH-to-HTTPS rewriting) to find the LFS server URL for a remote.
• Refs and history: resolve refspecs and tracking branches, walk commits with rev-list, and enumerate LFS pointer blobs reachable from a set of refs (drives fetch, pull, push, prune).
• Object access: long-lived cat-file --batch and --batch-check workers for blob inspection, plus git diff-index output parsing for pre-push.
• Attributes: a .gitattributes parser and matcher backed by gix-attributes and gix-glob.
• Packet-line framing: the pkt-line protocol used by filter-process to multiplex many filter operations in one subprocess.