Fix version and release date in the package distribution

.github/workflows/release.yml

@@ -38,6 +38,13 @@ jobs:
             exit 1
           fi
 
+      - name: Write release date into package
+        if: github.event_name == 'push'
+        run: |
+          RELEASE_DATE=$(git log -1 --format=%cs)
+          printf '"""Generated by the release workflow. Do not edit."""\n\nRELEASE_DATE = "%s"\n' "$RELEASE_DATE" > solarfarmer/_release_info.py
+          cat solarfarmer/_release_info.py
+
       - name: Build package
         run: uv build --sdist --wheel --out-dir dist/
 
@@ -54,7 +61,7 @@ jobs:
 
       - name: Verify package imports and list installed sizes
         run: |
-          PYTHONPATH=./tmp_install uv run python -c "import solarfarmer; print(solarfarmer.__version__)"
+          PYTHONPATH=./tmp_install uv run python -c "import solarfarmer; from solarfarmer.__version__ import __released__; print(solarfarmer.__version__, __released__)"
           du -h solarfarmer
         working-directory: ./tmp_install
 

.gitignore

@@ -11,6 +11,8 @@ venv/
 build/
 dist/
 *.egg-info/
+# Generated by the release workflow at build time
+solarfarmer/_release_info.py
 *.egg
 .eggs/
 

CHANGELOG.md

@@ -35,6 +35,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   "Narrow your search" message (e.g. `eff=9860.0%` is now `eff=98.6%`).
 - `PVSystem.payload_to_file()` now writes indented JSON instead of a single compact line, and keeps
   non-ASCII characters (e.g. in module or inverter file names) instead of escaping them as `\uXXXX`.
+- `solarfarmer.__version__` no longer returns `"unknown"` for pip-installed packages; it now reads the
+  metadata of the `dnv-solarfarmer` distribution.
+- `__released__` now reports the release date of installed wheels instead of `"unreleased"` or the tag
+  date of whichever git repository the user's working directory belonged to.
 
 ## [0.7.0] - 2026-10-07
 

solarfarmer/__version__.py

@@ -2,11 +2,14 @@
 
 This module provides version information with the following fallback chain:
 - __version__: Package metadata → pyproject.toml → "unknown"
-- __released__: Most recent git tag date → "unreleased" (development)
+- __released__: Build-time ``_release_info.py`` → SDK repo's latest git tag date → "unreleased"
 """
 
 __all__ = ["__version__", "__released__"]
 
+# Distribution name on PyPI (differs from the import package name "solarfarmer")
+_DISTRIBUTION_NAME = "dnv-solarfarmer"
+
 
 def _get_version():
     """Get version from package metadata, fallback to pyproject.toml for development.
@@ -18,7 +21,7 @@ def _get_version():
     try:
         from importlib.metadata import version
 
-        return version("solarfarmer")
+        return version(_DISTRIBUTION_NAME)
     except Exception:
         pass
 
@@ -51,33 +54,54 @@ def _get_version():
 
 
 def _get_release_date():
-    """Get release date from most recent git tag.
+    """Get the release date of the installed SDK.
+
+    Released wheels ship a ``_release_info.py`` module generated by the release
+    workflow. For source checkouts, the date of the latest tag in the SDK's own
+    git repository is used instead.
 
     Returns:
-        str: ISO date string (YYYY-MM-DD) of last tagged release,
-             or "unreleased" if no tags exist (development mode).
+        str: ISO date string (YYYY-MM-DD) of the release,
+             or "unreleased" if it cannot be determined (development mode).
     """
+    try:
+        from ._release_info import RELEASE_DATE
+
+        return RELEASE_DATE
+    except ImportError:
+        pass
+
     import subprocess
+    from pathlib import Path
 
+    repo_root = Path(__file__).resolve().parents[1]
     try:
-        # Get the date of the most recent tag
-        result = subprocess.run(
-            ["git", "log", "-1", "--format=%ci", "--tags", "--no-walk"],
+        # Only trust git if the package lives in its own checkout; otherwise an
+        # install inside an unrelated repo would report that repo's tag dates.
+        toplevel = subprocess.run(
+            ["git", "rev-parse", "--show-toplevel"],
             capture_output=True,
             text=True,
             check=False,
             timeout=2,
-            cwd=None,  # Use current directory
+            cwd=repo_root,
         )
+        if toplevel.returncode != 0 or Path(toplevel.stdout.strip()).resolve() != repo_root:
+            return "unreleased"
 
+        result = subprocess.run(
+            ["git", "log", "-1", "--format=%cs", "--tags", "--no-walk"],
+            capture_output=True,
+            text=True,
+            check=False,
+            timeout=2,
+            cwd=repo_root,
+        )
         if result.returncode == 0 and result.stdout.strip():
-            # Parse git date format: "2026-02-23 10:30:45 +0100"
-            date_str = result.stdout.strip().split()[0]
-            return date_str
+            return result.stdout.strip()
     except Exception:
         pass
 
-    # If no tags exist, this is unreleased development version
     return "unreleased"