Byron · Nov 5, 2026 · Nov 5, 2026 · Nov 5, 2026 · Nov 5, 2026 · Nov 5, 2026
diff --git a/.github/workflows/alpine-test.yml b/.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

diff --git a/.github/workflows/backend-benchmark.yml b/.github/workflows/backend-benchmark.yml
@@ -16,7 +16,6 @@ jobs:
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
-          fetch-depth: 0
           persist-credentials: false
       - uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7.1.0
         with:
@@ -50,7 +49,8 @@ jobs:
           .bench-gix/bin/python -m pip install '.[gix]' -r test/performance/benchmark-requirements.txt
       - name: Prepare the shared read-only benchmark fixture
         run: |
-          .bench-cli/bin/python -c 'from pathlib import Path; from gix import testtools; print("BENCH_REPO=" + str((testtools.scripted_fixture_read_only_with_args("benchmark.sh", [str(Path.cwd())]) / "repo").resolve()))' >> "$GITHUB_ENV"
+          rm -rf .git
+          .bench-cli/bin/python -c 'from gix import testtools; print("BENCH_REPO=" + str((testtools.scripted_fixture_read_only_with_args("benchmark.sh", []) / "repo").resolve()))' >> "$GITHUB_ENV"
           mkdir benchmark-results
       - name: Measure GixPython operations, opening and discovery first
         env:

diff --git a/.github/workflows/cygwin-test.yml b/.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"

diff --git a/.github/workflows/dependencies.yml b/.github/workflows/dependencies.yml
@@ -30,7 +30,6 @@ jobs:
     steps:
     - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       with:
-        fetch-depth: 0
         persist-credentials: false
     - uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7.1.0
       with:
@@ -45,8 +44,9 @@ jobs:
       run: flake8 "$PROJECT/$PROJECT" --count --select=E9,F63,F7,F82 --show-source --statistics
     - name: Test
       run: |
+        rm -rf .git
         if test "$PROJECT" = gitdb; then
-          GITDB_TEST_GIT_REPO_BASE="$(git rev-parse --git-common-dir)" pytest -o addopts= -v gitdb/gitdb/test
+          pytest -o addopts= -v gitdb/gitdb/test
         else
           pytest -o addopts= -v smmap/smmap/test
         fi

diff --git a/.github/workflows/pythonpackage.yml b/.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

diff --git a/CONTRIBUTING.md b/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

diff --git a/README.md b/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
 

diff --git a/doc/gix-backend.md b/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.

diff --git a/gitdb/README.rst b/gitdb/README.rst
@@ -42,6 +42,9 @@ The source is available in the GitPython repository on GitHub:
 
 https://github.com/gitpython-developers/GitPython/tree/main/gitdb
 
+Tests require Git and Bash. Each test class gets a temporary repository generated
+from scratch with packed and loose objects; no source checkout history is needed.
+
 Run the tests with::
 
  pytest

diff --git a/gitdb/gitdb/test/fixtures/repository.sh b/gitdb/gitdb/test/fixtures/repository.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -eu
+git init -q --object-format=sha1 -b main repo
+cd repo
+for n in $(seq 1 30); do
+    printf 'revision %s\n' "$n" >> file
+    git add file
+    git commit -qm "Revision $n"
+done
+git gc --prune=now
+# Keep both packed and loose objects for the compound database and tutorial tests.
+printf 'loose object\n' > loose
+git add loose
+git commit -qm 'Add loose objects'
diff --git a/gitdb/gitdb/test/lib.py b/gitdb/gitdb/test/lib.py
@@ -17,7 +17,7 @@
 import shutil
 import os
 import gc
-import logging
+import subprocess
 from functools import wraps
 
 
@@ -30,28 +30,28 @@ class TestBase(unittest.TestCase):
 
     * gitrepopath
 
-     * read-only base path of the git source repository, i.e. .../git/.git
+     * base path of a generated repository containing packed and loose objects
     """
 
-    #{ Invvariants
-    k_env_git_repo = "GITDB_TEST_GIT_REPO_BASE"
-    #} END invariants
-
     @classmethod
     def setUpClass(cls):
         try:
             super().setUpClass()
         except AttributeError:
             pass
 
-        cls.gitrepopath = os.environ.get(cls.k_env_git_repo)
-        if not cls.gitrepopath:
-            logging.info(
-                "You can set the %s environment variable to a .git repository of your choice - defaulting to the gitdb repository", cls.k_env_git_repo)
-            ospd = os.path.dirname
-            cls.gitrepopath = os.path.join(ospd(ospd(ospd(__file__))), '.git')
-        # end assure gitrepo is set
-        assert cls.gitrepopath.endswith('.git')
+        temporary = tempfile.TemporaryDirectory(prefix="gitdb-fixture-")
+        cls.addClassCleanup(temporary.cleanup)
+        env = {key: value for key, value in os.environ.items() if not key.startswith('GIT_')}
+        env.update(
+            GIT_CONFIG_NOSYSTEM='1', GIT_CONFIG_GLOBAL=os.devnull,
+            GIT_AUTHOR_NAME='GitDB Tests', GIT_AUTHOR_EMAIL='tests@example.invalid',
+            GIT_COMMITTER_NAME='GitDB Tests', GIT_COMMITTER_EMAIL='tests@example.invalid',
+            GIT_AUTHOR_DATE='2001-01-01T00:00:00 +0000', GIT_COMMITTER_DATE='2001-01-01T00:00:00 +0000',
+        )
+        # Keep the standalone suite usable on Python 3.8 without GixPython.
+        subprocess.run(['bash', fixture_path('repository.sh')], cwd=temporary.name, env=env, check=True)
+        cls.gitrepopath = os.path.join(temporary.name, 'repo', '.git')
 
 
 #} END bases

diff --git a/gitdb/gitdb/test/performance/test_pack.py b/gitdb/gitdb/test/performance/test_pack.py
@@ -51,7 +51,7 @@ def test_pack_random_access(self):
         # END for each random mode
 
         # query info and streams only
-        max_items = 10000           # can wait longer when testing memory
+        max_items = min(10000, ns)  # can wait longer when testing memory
         for pdb_fun in (pdb.info, pdb.stream):
             st = time()
             for sha in sha_list[:max_items]:
@@ -62,7 +62,7 @@ def test_pack_random_access(self):
         # END for each function
 
         # retrieve stream and read all
-        max_items = 5000
+        max_items = min(5000, ns)
         pdb_stream = pdb.stream
         total_size = 0
         st = time()

diff --git a/gitdb/gitdb/test/performance/test_pack_streaming.py b/gitdb/gitdb/test/performance/test_pack_streaming.py
@@ -49,10 +49,10 @@ def test_pack_writing(self):
         # END gather objects for pack-writing
         elapsed = time() - st
         print("PDB Streaming: Got %i streams by sha in in %f s ( %f streams/s )" %
-              (ni, elapsed, ni / (elapsed or 1)), file=sys.stderr)
+              (count, elapsed, count / (elapsed or 1)), file=sys.stderr)
 
         st = time()
-        PackEntity.write_pack((pdb.stream(sha) for sha in pdb.sha_iter()), ostream.write, object_count=ni)
+        PackEntity.write_pack((pdb.stream(sha) for sha in pdb.sha_iter()), ostream.write, object_count=pdb.size())
         elapsed = time() - st
         total_kb = ostream.bytes_written() / 1000
         print(sys.stderr, "PDB Streaming: Wrote pack of size %i kb in %f s (%f kb/s)" %
@@ -78,4 +78,4 @@ def test_stream_reading(self):
         elapsed = time() - st
         total_kib = total_size / 1000
         print(sys.stderr, "PDB Streaming: Got %i streams by sha and read all bytes totallying %i KiB ( %f KiB / s ) in %f s ( %f streams/s )" %
-              (ni, total_kib, total_kib / (elapsed or 1), elapsed, ni / (elapsed or 1)), sys.stderr)
+              (count, total_kib, total_kib / (elapsed or 1), elapsed, count / (elapsed or 1)), sys.stderr)
diff --git a/init-tests-after-clone.sh b/init-tests-after-clone.sh