Fix Repo() autodiscovery in linked worktrees when GIT_DIR is set by meliezer · Pull Request #2128 · gitpython-developers/GitPython

meliezer · 2026-04-20T10:04:08Z

Fixes #2022

This PR fixes repository autodiscovery in linked worktrees when GIT_DIR is set.

Summary

Fix Repo() autodiscovery when GIT_DIR points to a linked worktree git directory.

Previously, calling Repo() inside a linked worktree with GIT_DIR=$(git rev-parse --git-dir) could fail with InvalidGitRepositoryError, while Repo(os.getcwd()) resolved the repository correctly.

Changes

add regression coverage for autodiscovery in linked worktrees when GIT_DIR is set
detect linked worktree git directories during repository discovery
derive the working tree directory correctly from the linked worktree metadata

Reproduction

Inside a linked worktree:

export GIT_DIR=$(git rev-parse --git-dir)
python -c "from git import Repo; Repo()"

Before: raises InvalidGitRepositoryError
After: resolves repository correctly

Copilot

Pull request overview

Fixes git.Repo() autodiscovery when invoked from within a linked worktree and GIT_DIR is set to that worktree’s internal git directory (e.g. .git/worktrees/<id>), preventing erroneous InvalidGitRepositoryError.

Changes:

Added a regression test covering Repo() autodiscovery in a linked worktree with GIT_DIR set.
Updated repository discovery to recognize linked-worktree git directories by their metadata files.
Derived the correct working tree directory from linked worktree metadata during discovery.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
`test/test_repo.py`	Adds regression coverage ensuring `Repo()` works when `GIT_DIR` is set inside a linked worktree.
`git/repo/base.py`	Extends autodiscovery logic to detect linked-worktree git dirs and compute the correct working tree directory.

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Byron

Thanks.

In all honesty, I'm unable to tell if this makes any sense and if this is what Git does. But all we have is tests and as it doesn't break anything probably it's good enough.

Something I'd appreciate is the error message of the test when the patch here is not applied.

Besides that, I think a couple of changes are necessary.

Byron · 2026-04-20T23:52:00Z

            # It's important to normalize the paths, as submodules will otherwise
            # initialize their repo instances with paths that depend on path-portions
            # that will not exist after being removed. It's just cleaner.
+            if (


It seems the comment above this hunk was actually meant for the block below it. So that should be changed. I also think the code block can use some documentation on what it's trying to do.

@meliezer this wasn't addressed though. The comment above wants to be above if is_git_dir(curpath):.

Byron · 2026-04-20T23:53:10Z

+                and osp.isfile(osp.join(curpath, "HEAD"))
+            ):
+                git_dir = curpath
+                worktree_gitfile = Path(osp.join(git_dir, "gitdir")).read_text().splitlines()[0].strip()


Read text is probably going to fail given that the path can contain any set of characters without necessarily being in the default encoding.
Is there some utility in the code pase already that can read files that contain a gitdir?

Byron · 2026-04-20T23:55:46Z

+                if "GIT_WORK_TREE" in os.environ:
+                    self._working_tree_dir = os.getenv("GIT_WORK_TREE")


The _working_tree_dir probably starts out as None, and should be set by whatever has the final say, probably the environment variable.
Then if it's not yet set, all this extra work can be done to figure out the worktree dir.

meliezer · 2026-04-21T16:00:17Z

Addressed, thanks — I gave precedence to GIT_WORK_TREE, adjusted the comment, and replaced Path.read_text(). The linked worktree gitdir file uses a different format, so I handled it locally.

Handle linked worktree git directories when GIT_DIR points to .git/worktrees/<name>. Previously Repo() could fail with InvalidGitRepositoryError in this scenario, while Repo(os.getcwd()) worked correctly. Add regression test to cover autodiscovery in linked worktrees.

Byron · 2026-04-22T01:58:13Z

Thanks, just one piece missing.

Copilot

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

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Copilot · 2026-04-22T02:01:25Z

+        with mock.patch.dict(os.environ, {"GIT_DIR": git_dir}, clear=False):
+            old_cwd = os.getcwd()
+            try:
+                os.chdir(worktree_path)
+
+                explicit = Repo(os.getcwd())
+                autodiscovered = Repo()


This test patches only GIT_DIR but leaves any pre-existing GIT_WORK_TREE in the environment intact. If a user/CI environment has GIT_WORK_TREE set, Repo() will yield to it and the assertions will fail, making the test non-hermetic. Consider explicitly unsetting/removing GIT_WORK_TREE (and possibly GIT_COMMON_DIR) within this context so the test isolates the intended behavior.

meliezer force-pushed the fix-worktree-git-dir branch 2 times, most recently from a98c43b to b0354d5 Compare April 20, 2026 10:44

Byron requested a review from Copilot April 20, 2026 13:55

Copilot started reviewing on behalf of Byron April 20, 2026 13:56 View session

Copilot AI reviewed Apr 20, 2026

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Byron requested changes Apr 20, 2026

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meliezer force-pushed the fix-worktree-git-dir branch from b0354d5 to 3a94f7c Compare April 21, 2026 15:57

meliezer force-pushed the fix-worktree-git-dir branch from 3a94f7c to b5eb249 Compare April 21, 2026 16:07

Byron requested a review from Copilot April 22, 2026 01:56

Copilot started reviewing on behalf of Byron April 22, 2026 01:56 View session

Copilot AI reviewed Apr 22, 2026

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Fix Repo() autodiscovery in linked worktrees when GIT_DIR is set#2128

Fix Repo() autodiscovery in linked worktrees when GIT_DIR is set#2128
meliezer wants to merge 1 commit intogitpython-developers:mainfrom
meliezer:fix-worktree-git-dir

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		if "GIT_WORK_TREE" in os.environ:
		self._working_tree_dir = os.getenv("GIT_WORK_TREE")

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meliezer commented Apr 20, 2026

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