test: isolate repository fixtures from checkout history

Make PR and post-merge test results independent of checkout depth, refs,
and history. The shared test repository and dependency clone sources
previously came from the source checkout, requiring historical objects
and a bootstrap script even though setup already used `gix.testtools`.

Generate small repositories from scratch through `gix.testtools`, with
named root, release, merge, conflict, rename, date, and submodule states.
Adapt legacy assertions to those scenarios while retaining merge,
serialization, traversal, index, remote, and nested-submodule coverage.
Make dirty-submodule removal checks explicit for staged, unstaged, and
untracked data, including dry runs.

Remove the source-history environment override, dependency factory,
checkout lock cleanup, and bootstrap script. The main CI suites now use
shallow checkouts and remove source `.git` metadata before pytest. Add a
regression that initializes the shared fixture from a source copy without
Git metadata, and document the isolation requirement. Hash raw parser
samples in cache arguments to avoid archive filename limits on cold runs.

Validation: complete CLI and Gix suites from separate source copies with
no `.git`, including network-marked tests with local installation wheels.
Focused reruns of the two corrected cold-cache parser failures and the
adjusted serialization, tree-merge, and submodule-removal cases pass on
both backends.
Ruff lint/format, mypy, basedpyright, ShellCheck, YAML parsing, and
`git diff --check` pass. Linux and Windows CI have not been run locally.

Agent-Model: gpt-6-astra

Author: codex

.github/workflows/alpine-test.yml

@@ -34,18 +34,13 @@ jobs:
 
     - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       with:
-        fetch-depth: 0
         persist-credentials: false
 
     - name: Set workspace ownership
       run: |
         chown -R runner:docker -- "$GITHUB_WORKSPACE"
       shell: sh -exo pipefail {0}  # Run this as root, not the "runner" user.
 
-    - name: Prepare this repo for tests
-      run: |
-        ./init-tests-after-clone.sh
-
     - name: Set git user identity and command aliases for the tests
       run: |
         git config --global user.email "travis@ci.com"
@@ -95,6 +90,9 @@ jobs:
         python --version
         python -c 'import os, sys; print(f"{sys.platform=}, {os.name=}")'
 
+    - name: Remove source Git metadata to verify fixture isolation
+      run: .venv/bin/python -c "from pathlib import Path; from git.util import rmtree; rmtree('.git'); assert not Path('.git').exists()"
+
     - name: Test with pytest
       run: |
         . .venv/bin/activate

.github/workflows/cygwin-test.yml

@@ -30,7 +30,6 @@ jobs:
 
     - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       with:
-        fetch-depth: 0
         persist-credentials: false
 
     - name: Install Cygwin
@@ -61,10 +60,6 @@ jobs:
         git config --global --add safe.directory "$(pwd)/.git"
         git config --global core.autocrlf false
 
-    - name: Prepare this repo for tests
-      run: |
-        ./init-tests-after-clone.sh
-
     - name: Set git user identity and command aliases for the tests
       run: |
         git config --global user.email "travis@ci.com"

.github/workflows/pythonpackage.yml

@@ -61,7 +61,6 @@ jobs:
     steps:
     - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       with:
-        fetch-depth: 0
         persist-credentials: false
 
     - name: Set up Python ${{ matrix.python-version }}
@@ -115,10 +114,6 @@ jobs:
         brew install git
         echo "$(brew --prefix git)/bin" >> "$GITHUB_PATH"
 
-    - name: Prepare this repo for tests
-      run: |
-        ./init-tests-after-clone.sh
-
     - name: Set git user identity and command aliases for the tests
       run: |
         git config --global user.email "travis@ci.com"
@@ -219,6 +214,9 @@ jobs:
       run: |
         basedpyright --warnings
 
+    - name: Remove source Git metadata to verify fixture isolation
+      run: python -c "from pathlib import Path; from git.util import rmtree; rmtree('.git'); assert not Path('.git').exists()"
+
     - name: Test with pytest
       run: |
         if [[ "$RUNNER_OS" == "Windows" && -z "${GIT_PYTHON_GIT_EXECUTABLE+x}" ]]; then

CONTRIBUTING.md

@@ -3,7 +3,8 @@
 The following is a short step-by-step rundown of what one typically would do to contribute.
 
 - [Fork this project](https://github.com/gitpython-developers/GitPython/fork) on GitHub.
-- For setting up the environment to run the self tests, please run `init-tests-after-clone.sh`.
+- Install the `test` extra and select a backend before running `pytest`. Test
+  repositories are generated automatically; no source Git history is required.
 - Please try to **write a test that fails unless the contribution is present.**
 - Try to avoid massive commits and prefer to take small steps, with one commit for each.
 - Feel free to add yourself to AUTHORS file.
@@ -64,8 +65,10 @@ Put initial repository and filesystem states in `tests/fixtures/*.sh` and use
 `test.lib.fixtures` to run them through `gix.testtools`. Read-only tests share
 cached output; mutating tests use writable copies. Use `execute=True` only when
 the fixture cannot be copied, and explain the reason at its call site. Keep
-operations under test in Python. Immutable parser byte samples remain in
-`test/fixtures`; generated caches and archives are ignored.
+operations under test in Python. Generate histories from scratch and refer to
+named fixture revisions; do not clone the source checkout, fetch project history,
+or depend on its refs, object IDs, index, or working-tree state. Immutable parser
+byte samples remain in `test/fixtures`; generated caches and archives are ignored.
 
 Use `test.cleanup.cleanup_directory` for cleanup outside the shared fixture
 owners. Close repository handles before removing their files. Cleanup is

README.md

@@ -118,11 +118,8 @@ To clone the [the GitHub repository](https://github.com/gitpython-developers/Git
 ```sh
 git clone https://github.com/gitpython-developers/GitPython
 cd GitPython
-./init-tests-after-clone.sh
 ```
 
-On Windows, `./init-tests-after-clone.sh` can be run in a Git Bash shell.
-
 If you are cloning [your own fork](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/about-forks), then replace the above `git clone` command with one that gives the URL of your fork. Or use this [`gh`](https://cli.github.com/) command (assuming you have `gh` and your fork is called `GitPython`):
 
 ```sh
@@ -175,9 +172,8 @@ See [Issue #525](https://github.com/gitpython-developers/GitPython/issues/525).
 
 ### RUNNING TESTS
 
-_Important_: Right after cloning this repository, please be sure to have executed
-the `./init-tests-after-clone.sh` script in the repository root. Otherwise
-you will encounter test failures.
+Test repositories are generated from scratch by fixture scripts. Tests work from
+a shallow clone or a source copy without `.git`; no checkout preparation is needed.
 
 #### Install test dependencies
 

doc/gix-backend.md

@@ -214,6 +214,10 @@ installation/import smoke coverage, including the Cygwin Python 3.9 job.
 Running tests also requires Bash and Git 2.52+; `gix` here is GixPython's module.
 
 Initial repository and filesystem states live in `tests/fixtures/*.sh`.
+Histories are generated from scratch, including the shared sample repository and
+its nested dependency repositories. Tests use named revisions such as `root`,
+`release`, and `merge`, and require no source checkout history or Git metadata.
+CI removes the source `.git` directory before running the full suite.
 `test/lib/fixtures.py` calls `gix.testtools` with an explicit lifetime:
 
 - `read_only_fixture()` and the default `fixture_repo()` reuse cached output.

init-tests-after-clone.sh

@@ -5,11 +5,8 @@
 from pathlib import Path
 
 import pytest
-from gix import testtools
 
 from git import _backend
-from test.lib import GIT_REPO, TestBase
-from test.lib.fixtures import read_only_fixture
 
 
 def pytest_addoption(parser):
@@ -99,29 +96,3 @@ def pytest_terminal_summary(terminalreporter, exitstatus, config):
         with open(path, "w", encoding="utf-8") as stream:
             json.dump(records, stream, indent=2)
             stream.write("\n")
-
-
-@pytest.fixture(scope="session")
-def dependency_repo_factory():
-    """Prepare each immutable historical clone source only when a test needs it."""
-    source = Path(GIT_REPO).resolve()
-    revision = testtools.git(source, "rev-parse HEAD").strip()
-    paths = {}
-
-    def get(name):
-        if name not in paths:
-            paths[name] = str(read_only_fixture("dependencies.sh", source, revision, name) / "repo")
-        return paths[name]
-
-    return get
-
-
-@pytest.fixture(scope="class", autouse=True)
-def historical_dependency_sources(request):
-    if request.cls is not None and issubclass(request.cls, TestBase):
-        factory = request.getfixturevalue("dependency_repo_factory")
-        request.cls._dependency_repo_factory = staticmethod(factory)
-        yield
-        del request.cls._dependency_repo_factory
-    else:
-        yield

test/conftest.py

@@ -16,7 +16,6 @@
     "TestCase",
     "SkipTest",
     "skipIf",
-    "GIT_REPO",
     "GIT_DAEMON_PORT",
     "xfail_if_raises",
     "symlinks_supported",
@@ -31,7 +30,6 @@
 import logging
 import os
 import os.path as osp
-from pathlib import Path
 from stat import S_ISLNK, ST_MODE
 import socket
 import textwrap
@@ -41,7 +39,6 @@
 from typing import Union, Type, Tuple
 
 import pytest
-from gix import testtools
 
 from git.util import cwd
 from test.cleanup import TemporaryDirectory
@@ -53,7 +50,6 @@
 
 ospd = osp.dirname
 
-GIT_REPO = os.environ.get("GIT_PYTHON_TEST_GIT_REPO_BASE", ospd(ospd(ospd(__file__))))
 GIT_DAEMON_PORT = os.environ.get("GIT_PYTHON_TEST_GIT_DAEMON_PORT", "19418")
 
 _logger = logging.getLogger(__name__)
@@ -373,22 +369,21 @@ class TestBase(TestCase):
 
         self.rorepo  # 'ro' stands for read-only
 
-      The rorepo is a scripted clone of your project's git repo. If you refer to specific
-      shas for your objects, be sure you choose some that are part of the immutable
-      portion of the project history (so that tests don't fail for others).
+      The rorepo is generated by sample-repositories.sh. Its named revisions describe
+      the test scenarios and do not depend on the project's checkout or history.
     """
 
     def _small_repo_url(self):
         """:return: A path to a small, clonable repository"""
         from git.cmd import Git
 
-        return Git.polish_url(self._dependency_repo_factory("smmap"))
+        return Git.polish_url(str(read_only_fixture("sample-repositories.sh") / "smmap"))
 
     def _gitdb_repo_url(self):
-        """:return: A local gitdb repository reconstructed from merged history"""
+        """:return: A generated repository with a nested submodule"""
         from git.cmd import Git
 
-        return Git.polish_url(self._dependency_repo_factory("gitdb"))
+        return Git.polish_url(str(read_only_fixture("sample-repositories.sh") / "gitdb"))
 
     @classmethod
     def setUpClass(cls):
@@ -399,9 +394,7 @@ def setUpClass(cls):
         from git import Repo
 
         gc.collect()
-        source = Path(GIT_REPO).resolve()
-        revision = testtools.git(source, "rev-parse HEAD").strip()
-        cls.rorepo = Repo(read_only_fixture("history.sh", source, revision, revision, "baseline") / "repo")
+        cls.rorepo = Repo(read_only_fixture("sample-repositories.sh") / "repo")
 
     @classmethod
     def tearDownClass(cls):