Hi Karthik,

Thanks for the detailed feedback. I revised the proposal draft to make the current status, intended scope, patch breakdown, and use of existing tests clearer. The updated draft is below.

Improve Git Repo Info By Adding Repository Path Metadata

Name Jialong Wang

Email jerrywang183@yahoo.com

Preferred project size 175 hours

About me

My name is Jialong Wang, and I plan to apply to Git for GSoC 2026.

I have been getting familiar with Git's development workflow by building Git from source, reading the contribution documents, and working on a microproject. My microproject focused on improving corrupt patch location reporting in git apply and git am. That work has already gone through mailing list review, including comments from Karthik Nayak and Junio C Hamano, and it gave me direct experience with rerolling patches, updating tests, and using CI to catch gaps that I had missed locally.

My broader programming experience has mainly involved systems-oriented software, where I have had to read existing code, trace behavior through unfamiliar paths, and make targeted changes without disrupting surrounding logic.

At this point, my recent Git contributions around this microproject are:

1. an initial microproject patch series to report the location of
   corrupt patches more clearly
2. a follow-up patch to report input locations in header parsing errors
   in apply.c
3. a follow-up patch to report input locations in binary and garbage
   patch error paths in apply.c

This has also helped me get comfortable with the normal Git workflow of starting with a small change, responding to review, and then continuing with a logically related follow-up.

I am interested in the new git repo command because it is user-facing, but also closely tied to Git's internal repository model. That makes it a good fit for the kind of work I want to do: understanding existing code, discussing design details on the mailing list, and implementing improvements in small, reviewable patches.

Relevant links

Microproject discussion thread This thread asked whether improving corrupt patch location reporting was a suitable microproject and helped me choose the work. https://public-inbox.org/git/CAKWWG_nGhD6vqhAS1mkEwBQPrg_YX0+C3-xW=Q3ifFDw4dDviw@mail.gmail.com/

Microproject patch thread This thread contains the patch itself, review, and rerolls for the corrupt patch location reporting work. https://public-inbox.org/git/20260315231538.68586-1-jerrywang183@yahoo.com/

Follow-up patch This follow-up patch extends the same idea to header parsing errors in apply.c. https://public-inbox.org/git/20260316195847.92386-1-jerrywang183@yahoo.com/

Second follow-up patch
This follow-up patch extends the same idea to binary and garbage patch
error paths in apply.c and has also been sent to the mailing list. I
will add the public archive link once it is indexed.
Subject: [GSoC PATCH] apply: report input location in binary and garbage patch errors

SoC 2026 idea page https://git.github.io/SoC-2026-Ideas/

Project summary

I would like to work on improving the new git repo command, with a primary focus on git repo info.

The git repo command was introduced to provide a cleaner interface for querying repository metadata. However, several useful path-related values are still mainly accessed through git rev-parse and git rev-parse --git-path. My proposal is to extend git repo info so that it can expose a selected set of those values in a more structured form.

The goal is not to replace git rev-parse, but to make git repo info more useful as a structured interface for repository path metadata.

Motivation

Today, scripts and tools still often rely on commands such as:

git rev-parse --git-dir git rev-parse --show-toplevel git rev-parse --git-path <path>

These commands are useful, but they were not primarily designed as a structured repository metadata interface.

Since git repo info already exists for this purpose, extending it with path-related values would make repository layout information easier to query in a cleaner and more consistent way.

I think this is a good GSoC project because it has clear user value, can be implemented incrementally, and naturally fits Git's patch-and-review workflow.

Current context

I am aware that work on path-related git repo info fields has already started. There have already been patch series for path keys, category requests, and path formatting. Because of that, I do not want to assume that the work described on the ideas page is still untouched.

One of my first goals during the bonding period would be to review the current state of these discussions carefully, identify what remains open, and refine the project scope based on maintainer feedback. I would rather build on the current direction than duplicate work that is already in progress.

My recent apply.c follow-up patches are separate from git repo itself, but they have already helped me get comfortable with Git's mailing list process, with responding to maintainer comments, and with organizing small changes into follow-up patches instead of overloading a single series. I expect to approach git repo work in the same way.

At the moment, the direction that seems most realistic to me is to start with a small set of layout-related fields that already have clear equivalents in git rev-parse, such as git-dir, common-dir, toplevel, and superproject-working-tree. I would prefer to begin there before taking on broader questions such as category-wide output or possible git repo structure extensions.

More concretely, if the current discussions do not point in a different direction, I would expect my first implementation work to focus on a small initial series that adds one or a few of these layout-related fields to git repo info, together with tests and documentation for the same behavior. I would treat that first series as the point where the community can judge whether the field naming, path representation, and overall shape of the interface look right before I continue to a second batch.

In other words, my current preference is:

1. first settle a small batch of repo info path fields with clear
   rev-parse equivalents
2. then extend to a second batch of agreed path-related values from
   rev-parse --git-path
3. only after that consider whether category keys or other nearby repo
   info improvements are worth taking on as stretch work

I also think this project should be scoped carefully. The ideas page mentions improvements to both git repo info and git repo structure, but for a GSoC project I believe it is more realistic to focus first on git repo info and only expand beyond that if the main work is in good shape.

Proposed work

The main objective of this project is to extend git repo info with selected repository path values that are currently obtained through git rev-parse and git rev-parse --git-path.

I expect the work to proceed in four connected parts:

1. Review the current implementation and ongoing mailing list
   discussions, then narrow the initial scope to a first small batch of
   path-related fields.
2. Discuss output design on the mailing list, especially where there are
   open questions about relative versus absolute paths and how the new
   fields should fit the existing interface.
3. Implement the agreed functionality through small patch series, with
   each patch or small patch group carrying its own tests and any
   documentation updates for the user-visible behavior.
4. If the first batch is in good shape, extend support to a second
   agreed batch of path-related fields.

Initial scope

The first stage of the project would focus on a small set of commonly used repository path values, for example:

git-dir common-dir toplevel superproject-working-tree

I think these are a good first target because they are already familiar to users through git rev-parse, and they provide immediate practical value without requiring a large interface expansion.

If I had to choose an initial implementation order today, I would most likely start with git-dir, common-dir, and toplevel first, because they seem like the most direct and broadly useful candidates. I would then look at superproject-working-tree and selected git-path style values after the first review round, rather than trying to push all of them in the same initial series.

Depending on project progress and mailing list feedback, I would then like to extend support to selected values currently accessed through git rev-parse --git-path, such as:

index file objects directory hooks directory

I do not want to promise every possible path-related key up front. I would rather start with the most straightforward and useful values, get feedback early, and continue from there.

If the core path-related work is in good shape, possible later work could include small extensions around category keys or closely related repo info behavior. I do not want to commit to that up front, but I do want the timeline to make room for it as stretch work rather than as a core deliverable.

My approach to scope and quality

One thing I would like to be careful about is not treating this project as a simple checklist of fields to add.

I think the quality of the project will depend on three things:

1. choosing a small set of fields that make sense together
2. agreeing on a consistent path representation
3. making sure the result fits naturally into the existing git repo
   design rather than becoming a thin wrapper over git rev-parse

Because of that, I would prefer to make progress in a few coherent batches instead of adding many unrelated keys at once.

I also think it is important to keep room for scope reduction. If some part of the design turns out to be more controversial than expected, I would prefer to complete a smaller, cleaner set of path fields rather than stretching the project too broadly.

Technical approach

The implementation of git repo is primarily in builtin/repo.c. The first step would be to understand how git repo info currently collects and prints repository metadata, and how that existing structure can be extended without making the interface inconsistent.

Many relevant repository paths are already available internally through helpers such as:

repo_get_git_dir() repo_get_common_dir() repo_get_work_tree()

Similarly, git rev-parse --git-path already relies on existing path resolution logic. So the work is not about inventing these values from scratch, but about exposing a selected subset of them through git repo info in a way that fits its current design.

The first implementation step would be to map existing helpers and path resolution logic to a small set of repo info fields. After that, I would extend the output code in builtin/repo.c to report those fields in a consistent way.

In the current implementation, git repo info is handled by cmd_repo_info() in builtin/repo.c. The currently supported keys are defined in repo_info_field[], and the command prints values through print_fields() and print_all_fields().

A likely first implementation step would be to add new entries to repo_info_field[] for the first batch of path-related keys, backed by new getter functions that fit alongside existing ones such as get_layout_bare(), get_layout_shallow(), get_object_format(), and get_references_format(). The main user-facing path through the command would still remain cmd_repo_info() together with the existing print_fields() and print_all_fields() flow, so my goal would be to extend that structure rather than introduce a separate special case for path values.

For the initial batch, my expectation is that the implementation will mostly look like:

1. identify which existing repository or path helper corresponds to the
   field to be exposed
2. add a getter that matches the shape expected by repo_info_field[]
3. register the new field in repo_info_field[]
4. update the output and tests to cover the new field
5. update the documentation for the new field and its path format

In practical terms, I expect the first series to stay close to the existing structure in builtin/repo.c rather than try to redesign it. If the early fields are backed cleanly by helpers such as repo_get_git_dir(), repo_get_common_dir(), or repo_get_work_tree(), I would prefer to start there and let review on those patches shape the approach for later fields.

For path-related values, the main work would not be inventing new data, but deciding which existing repository and path helpers should back each key and how those paths should be formatted consistently in git repo info.

One of the main design questions is path formatting. The ideas page explicitly mentions the need to decide between relative and absolute paths. I do not want to assume the answer in advance. Instead, I would review the current discussion, compare the behavior of existing commands, and propose a small, consistent approach on the mailing list.

I also expect that some preparatory cleanup or refactoring may be useful before adding new fields. If so, I would keep that work minimal and send it as small separate patches.

Patch strategy

I expect the implementation to be divided into small patches so that each change can be reviewed independently.

A likely patch strategy would be:

1. small preparatory cleanup if needed
2. add a first small batch of layout-related fields, together with the
   tests and documentation updates needed for those fields
3. extend support with additional agreed path-related fields, again with
   matching tests and documentation updates

For the first batch, I currently expect something on the order of 4 to 6 patches, depending on how much preparatory cleanup is useful and on whether tests and documentation read more clearly combined with the field patches or as separate follow-up patches in the same series. I do not want to promise an exact count in advance, but I do want the first series to stay small enough that each patch still has a clear purpose.

I do not want to treat tests and documentation as a final clean-up stage. Since these are user-visible additions to git repo info, I think the tests and documentation should evolve with each field batch, so that the mailing list can review the interface and its description at the same time as the implementation.

If existing in-progress series already cover some of these parts, I would adjust the breakdown accordingly and focus on what remains useful and open.

Tests

Tests would be added alongside the new behavior rather than at the very end.

Depending on the exact scope agreed on, test cases may include:

ordinary repositories linked worktrees superproject and submodule cases cases where path values differ from simple defaults

Where possible, I would compare the new git repo info output against existing git rev-parse behavior, since many of the proposed fields are already exposed there. I would also look for opportunities to reuse or mirror the same repository layouts and edge cases that are already important to rev-parse, instead of inventing unrelated test-only cases.

For fields whose behavior is intentionally meant to correspond closely to git rev-parse, I would like the tests to make that relationship clear. For example, if a new git repo info field is meant to expose the same information as a particular rev-parse query, I would try to test both in the same repository setup so that any differences are explicit and intentional rather than accidental.

I would keep the tests focused on observable behavior instead of overfitting them to a particular implementation detail.

What I will not try to do

To keep the project realistic, I do not plan to:

redesign all of git repo fully replace git rev-parse implement every possible repository path query work on both git repo info and git repo structure at full scope in the same project

The project should stay focused on a well-defined subset of path-related metadata for git repo info.

Expected deliverables

By the end of the project, I expect to deliver:

support for a useful set of path-related values in git repo info tests covering the new functionality for those fields documentation updates for the new fields and their behavior one or more patch series discussed and refined on the Git mailing list

Success criteria

I would consider the project successful if, by the end of the GSoC period, the following are true:

1. a first useful batch of path-related git repo info fields has been
   implemented and is in good shape on the mailing list, ideally merged
   or close to merge-ready
2. the new fields are covered by tests that clearly exercise the agreed
   repository layouts and path behavior
3. the documentation for those fields has been updated together with the
   implementation
4. if review and scope permit, at least one further agreed batch of
   fields has also been implemented or is well advanced

Timeline

Community bonding period

Study builtin/repo.c and the current git repo info implementation Review recent and ongoing mailing list discussions related to git repo Compare current git repo info behavior with git rev-parse Refine the exact scope with mentors and mailing list feedback Identify the first small batch of fields that looks realistic for an initial patch series Review whether any in-progress series already cover part of that first batch, so that I can avoid duplicating ongoing work

Week 1

Confirm the exact first batch of fields to target Prepare and send an initial patch series for that batch Include tests and documentation updates in that first series instead of leaving them to the end

Week 2

Address review comments on the initial series Revise the first batch if there is feedback about key naming, output shape, or relative versus absolute paths Decide whether the current direction is stable enough to continue with a second batch or whether the first batch needs another reroll first

Weeks 3 to 4

Address review comments on the initial series Refine the first batch if there is feedback about field naming or path formatting Settle the first round of tests and documentation If the first batch is accepted or close to settled, identify the exact second batch to work on next

Weeks 5 to 6

Implement a second agreed batch of path-related fields, likely selected git rev-parse --git-path equivalents Send the next patch series with tests and documentation updates for that batch Keep the second batch narrower than the first draft of the overall idea if review shows that path formatting or naming still needs discussion

Weeks 7 to 8

Address review comments on the second batch Refine edge cases involving worktrees, submodules, or path formatting Make sure the user-visible behavior is documented clearly for whatever subset of fields is actually agreed on

Weeks 9 to 10

Finish remaining agreed work Use the remaining time as buffer for rerolls, regressions, or scope reduction if needed If the core path-related work is in good shape, investigate a small stretch item closely related to git repo info rather than branching out into a separate large feature

Weeks 11 to 12

Handle any remaining review rounds on the core patch series Polish tests and documentation for the agreed set of fields Use the remaining time for final cleanup, rerolls, and project summary rather than for opening a new large piece of work

Core goals for the project

1. land or get close to landing a first useful batch of path-related
   git repo info fields
2. implement at least one further agreed batch if the first one is in
   good shape
3. keep tests and documentation updated as part of the patch series

Stretch work

1. add a small extra batch beyond the core set if review cycles go well
2. investigate a nearby repo info improvement such as a small category
   or interface refinement, but only if the main path-related work is
   already in good shape

Risks and mitigation

One risk is that design discussion may take longer than expected, especially around path representation and output structure.

To reduce that risk, I would keep the patch series small and prioritize the least controversial values first.

Another risk is overlap with work already in progress. If that happens, I would adjust the project scope to avoid duplication and focus on what is still useful and open.

Why I think I am a good fit

I have already started learning Git's normal contribution workflow through a microproject, including building Git from source, running tests, preparing patches, responding to review, and rerolling them on the mailing list.

This project is a good fit for me because it requires exactly the kind of work I have already started doing in Git: reading existing code paths carefully, making small user-visible improvements, and refining the result through review rather than trying to force a large one-shot design.

References

Official and technical references

SoC 2026 idea page https://git.github.io/SoC-2026-Ideas/

General application information https://git.github.io/General-Application-Information/

git repo documentation https://git-scm.com/docs/git-repo

git rev-parse documentation https://git-scm.com/docs/git-rev-parse

git-sizer project https://github.com/github/git-sizer

Relevant mailing list threads

Recent patch series adding path-related support to git repo https://public-inbox.org/git/20260228224252.72788-1-lucasseikioshiro@gmail.com/

More recent work-in-progress series for category and path keys and path-format https://public-inbox.org/git/pull.2208.v6.git.git.1772428548.gitgitgadget@gmail.com/

Recent GSoC proposal thread on improving the new git repo command https://public-inbox.org/git/20260303140732.16886-1-pushkarkumarsingh1970@gmail.com/

Another recent GSoC proposal thread on improving and extending git repo https://public-inbox.org/git/CA+rGoLd-1Mb5JG1H1PvE-kyjdznrLVFjwQiMLHtd2ETQ-igmXg@mail.gmail.com/

Recent proposal thread focused on the same SoC idea https://public-inbox.org/git/CAO_P5U3g_+RpnDUmEv_qX-3GVhpxLV97eMxP1apERc0KU_95tQ@mail.gmail.com/

Recent discussion around git repo structure enhancements https://public-inbox.org/git/CAO_P5U2f4MD-URre+4ocC=YQ570hr03pZHDk1jvuSOKx4aLOCA@mail.gmail.com/

Microproject discussion thread https://public-inbox.org/git/CAKWWG_nGhD6vqhAS1mkEwBQPrg_YX0+C3-xW=Q3ifFDw4dDviw@mail.gmail.com/

Microproject patch thread https://public-inbox.org/git/20260315231538.68586-1-jerrywang183@yahoo.com/

Review on the microproject patch thread https://public-inbox.org/git/CAOLa=ZTpfHUySnMgCFMnvo2JcRSv8zqFP-cLFSs+Ab5Cy2zsvg@mail.gmail.com/

Follow-up patch for header parsing errors https://public-inbox.org/git/20260316195847.92386-1-jerrywang183@yahoo.com/

Follow-up patch for binary and garbage patch errors
Sent to the mailing list; public archive link to be added once indexed.
Subject: [GSoC PATCH] apply: report input location in binary and garbage patch errors

Thanks, Jialong