Add requirements-reference.txt for reproducible Python deps (fixes #610)

- Add tools/tests/requirements-reference.txt with pinned versions
- Add update_requirements_reference.py to regenerate from reference_versions.yaml
- Add validate_requirements_reference.py to check pyprecice matches
- Add GitHub Action check-requirements-reference.yml
- Document in tools/tests/README.md and release PR template

Author: PranjalManhgaye

.github/pull_request_template.md

@@ -10,7 +10,9 @@ TODO
   - Add a [sidebar entry](https://github.com/precice/precice.github.io/blob/master/_data/sidebars/tutorial_sidebar.yml)
   - Add it to the [overview](https://github.com/precice/precice.github.io/blob/master/content/tutorials/tutorials.md)
 
+For **release PRs** (new distribution): update `tools/tests/requirements-reference.txt` if `reference_versions.yaml` changed (`python3 tools/tests/update_requirements_reference.py`).
+
 ## Resources
 
 - [Contributing tutorials](https://precice.org/community-contribute-to-precice.html#contributing-tutorials)
-- [System tests documentation](https://precice.org/dev-docs-system-tests.html)
+- [System tests documentation](https://precice.org/dev-docs-system-tests.html)

.github/workflows/check-requirements-reference.yml

@@ -0,0 +1,28 @@
+name: Check requirements-reference
+on:
+  push:
+    branches:
+      - master
+      - develop
+    paths:
+      - tools/tests/requirements-reference.txt
+      - tools/tests/reference_versions.yaml
+      - tools/tests/update_requirements_reference.py
+  pull_request:
+    branches:
+      - master
+      - develop
+    paths:
+      - tools/tests/requirements-reference.txt
+      - tools/tests/reference_versions.yaml
+      - tools/tests/update_requirements_reference.py
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+      - name: Validate requirements-reference
+        run: python3 tools/tests/validate_requirements_reference.py

changelog-entries/610.md

@@ -0,0 +1 @@
+- Add `requirements-reference.txt` (lockfile-style pinned Python versions) and `update_requirements_reference.py` for reproducible dependency versions per distribution (fixes [#610](https://github.com/precice/tutorials/issues/610)). Includes GitHub Action to validate pyprecice version matches `reference_versions.yaml`; release PR template reminder to update the reference file.

tools/tests/README.md

@@ -185,6 +185,25 @@ User-facing tools:
   - `print_case_combinations.py`: Prints all possible combinations of tutorial cases, using the `metadata.yaml` files.
   - `build_docker_images.py`: Build the Docker images for each test
   - `generate_reference_results.py`: Executes the system tests with the versions defined in `reference_versions.yaml` and generates the reference data archives, with the names described in `tests.yaml`. (should only be used by the CI Pipeline)
+  - `update_requirements_reference.py`: Regenerates `requirements-reference.txt` with pinned Python versions from `reference_versions.yaml` (for reproducibility, see issue #610).
+  - `validate_requirements_reference.py`: Validates that `requirements-reference.txt` exists and pyprecice version matches `reference_versions.yaml`.
+
+### requirements-reference.txt
+
+A lockfile-style list of pinned Python dependency versions (pyprecice, numpy, matplotlib, nutils, setuptools) for reproducible builds and distributions (see issue [#610](https://github.com/precice/tutorials/issues/610)). This file is a **reference manifest only**: tutorial `run.sh` scripts keep using their own `requirements.txt` (with loose constraints) to avoid merge back-and-forth; system tests use the Docker image’s venv. The reference file records “versions known to work” for a distribution.
+
+**Update at each release.** For best accuracy (match what CI uses), capture from the systemtest Docker image:
+
+```bash
+docker run --rm <python_bindings_or_fenics_image> pip freeze | python3 update_requirements_reference.py --from-freeze
+```
+
+Or regenerate from `reference_versions.yaml` only (pyprecice from PYTHON_BINDINGS_REF; others from script defaults):
+
+```bash
+cd tools/tests
+python3 update_requirements_reference.py
+```
 
 Implementation scripts:
 

tools/tests/requirements-reference.txt

@@ -0,0 +1,11 @@
+# Pinned Python dependency versions for reproducible system tests and distributions.
+# Generated from reference_versions.yaml (PYTHON_BINDINGS_REF). Update at each release.
+# Run: python3 update_requirements_reference.py
+#
+# See tools/tests/README.md for how to update this file.
+
+matplotlib==3.9.0
+numpy==1.26.4
+nutils==7.2
+pyprecice==3.2.0
+setuptools>=69.0.0

tools/tests/update_requirements_reference.py

@@ -0,0 +1,116 @@
+#!/usr/bin/env python3
+"""
+Update requirements-reference.txt with pinned versions from reference_versions.yaml.
+
+This script reads PYTHON_BINDINGS_REF from reference_versions.yaml and generates
+a requirements-reference.txt with pyprecice pinned to the corresponding version.
+Other common packages (numpy, matplotlib, setuptools) use fixed versions known
+to work with the tutorials.
+
+Run from tools/tests/:
+  python3 update_requirements_reference.py
+
+Or to regenerate from a pip freeze (e.g. from Docker):
+  pip freeze | python3 update_requirements_reference.py --from-freeze
+"""
+import argparse
+import re
+import sys
+from pathlib import Path
+
+REFERENCE_VERSIONS = Path(__file__).parent / "reference_versions.yaml"
+REQUIREMENTS_REF = Path(__file__).parent / "requirements-reference.txt"
+
+# Default pinned versions for common packages (fallback when not using --from-freeze)
+DEFAULTS = {
+    "matplotlib": "3.9.0",
+    "numpy": "1.26.4",
+    "nutils": "7.2",
+    "pyprecice": None,  # From reference_versions.yaml
+    "setuptools": ">=69.0.0",
+}
+
+# Packages to include (in order)
+PACKAGES = ["matplotlib", "numpy", "nutils", "pyprecice", "setuptools"]
+
+
+def get_pyprecice_version_from_ref(ref: str) -> str:
+    """Convert PYTHON_BINDINGS_REF (e.g. v3.2.0) to pyprecice version (3.2.0)."""
+    return ref.lstrip("v").strip()
+
+
+def load_reference_versions() -> str:
+    """Load PYTHON_BINDINGS_REF from reference_versions.yaml."""
+    text = REFERENCE_VERSIONS.read_text()
+    for line in text.splitlines():
+        if "PYTHON_BINDINGS_REF" in line and ":" in line:
+            match = re.search(r'["\']([^"\']+)["\']', line)
+            if match:
+                return match.group(1)
+    raise ValueError("PYTHON_BINDINGS_REF not found in reference_versions.yaml")
+
+
+def parse_freezed_packages(freezed: str) -> dict[str, str]:
+    """Parse pip freeze output into {package: version}."""
+    result = {}
+    for line in freezed.strip().splitlines():
+        line = line.strip()
+        if not line or line.startswith("#"):
+            continue
+        if "==" in line:
+            pkg, ver = line.split("==", 1)
+            result[pkg.lower()] = f"=={ver.strip()}"
+        elif "===" in line:
+            pkg, ver = line.split("===", 1)
+            result[pkg.lower()] = f"=={ver.strip()}"
+    return result
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Update requirements-reference.txt from reference_versions.yaml"
+    )
+    parser.add_argument(
+        "--from-freeze",
+        action="store_true",
+        help="Read pip freeze from stdin and use those versions for known packages",
+    )
+    args = parser.parse_args()
+
+    pyprecice_ref = load_reference_versions()
+    pyprecice_ver = get_pyprecice_version_from_ref(pyprecice_ref)
+
+    if args.from_freeze:
+        freezed = parse_freezed_packages(sys.stdin.read())
+        versions = {}
+        for pkg in PACKAGES:
+            if pkg.lower() in freezed:
+                versions[pkg] = freezed[pkg.lower()]
+            elif pkg == "pyprecice":
+                versions[pkg] = f"=={pyprecice_ver}"
+            elif DEFAULTS.get(pkg):
+                versions[pkg] = (
+                    DEFAULTS[pkg] if DEFAULTS[pkg].startswith(("==", ">=", "~=")) else f"=={DEFAULTS[pkg]}"
+                )
+    else:
+        DEFAULTS["pyprecice"] = pyprecice_ver
+        versions = {
+            pkg: f"=={ver}" if ver and not ver.startswith(("==", ">=", "~=")) else (ver or "")
+            for pkg, ver in DEFAULTS.items()
+        }
+        versions["pyprecice"] = f"=={pyprecice_ver}"
+
+    header = """# Pinned Python dependency versions for reproducible system tests and distributions.
+# Generated from reference_versions.yaml (PYTHON_BINDINGS_REF). Update at each release.
+# Run: python3 update_requirements_reference.py
+#
+# See tools/tests/README.md for how to update this file.
+
+"""
+    lines = [f"{pkg}{versions.get(pkg, '')}\n" for pkg in PACKAGES if pkg in versions]
+    REQUIREMENTS_REF.write_text(header + "".join(lines))
+    print(f"Wrote {REQUIREMENTS_REF} (pyprecice from {pyprecice_ref})")
+
+
+if __name__ == "__main__":
+    main()

tools/tests/validate_requirements_reference.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+"""
+Validate that requirements-reference.txt exists and pyprecice version
+matches PYTHON_BINDINGS_REF in reference_versions.yaml.
+
+Exit 0 on success, 1 on failure.
+"""
+import re
+import sys
+from pathlib import Path
+
+TOOLS_TESTS = Path(__file__).parent
+REFERENCE_VERSIONS = TOOLS_TESTS / "reference_versions.yaml"
+REQUIREMENTS_REF = TOOLS_TESTS / "requirements-reference.txt"
+
+
+def main() -> int:
+    if not REQUIREMENTS_REF.exists():
+        print(f"ERROR: {REQUIREMENTS_REF} not found. Run update_requirements_reference.py.", file=sys.stderr)
+        return 1
+
+    # Load PYTHON_BINDINGS_REF
+    ref_text = REFERENCE_VERSIONS.read_text()
+    ref_match = re.search(r'PYTHON_BINDINGS_REF:\s*["\']([^"\']+)["\']', ref_text)
+    if not ref_match:
+        print("ERROR: PYTHON_BINDINGS_REF not found in reference_versions.yaml", file=sys.stderr)
+        return 1
+
+    expected_ver = ref_match.group(1).lstrip("v").strip()
+
+    # Parse pyprecice from requirements-reference.txt
+    req_text = REQUIREMENTS_REF.read_text()
+    precice_match = re.search(r"pyprecice\s*==\s*([\w.]+)", req_text)
+    if not precice_match:
+        print("ERROR: pyprecice not found in requirements-reference.txt", file=sys.stderr)
+        return 1
+
+    actual_ver = precice_match.group(1).strip()
+    if actual_ver != expected_ver:
+        print(
+            f"ERROR: pyprecice version mismatch: requirements-reference.txt has {actual_ver}, "
+            f"reference_versions.yaml PYTHON_BINDINGS_REF has {ref_match.group(1)}. "
+            "Run: python3 update_requirements_reference.py",
+            file=sys.stderr,
+        )
+        return 1
+
+    print(f"OK: requirements-reference.txt pyprecice=={actual_ver} matches reference_versions.yaml")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())