Ensure default versions are always correct

relenv/build/__init__.py

@@ -15,8 +15,13 @@
 
 from . import darwin, linux, windows
 from .common import builds
-from ..common import DEFAULT_PYTHON, build_arch
-from ..pyversions import Version, python_versions
+from ..common import build_arch
+from ..pyversions import (
+    Version,
+    get_default_python_version,
+    python_versions,
+    resolve_python_version,
+)
 
 
 def platform_module() -> ModuleType:
@@ -62,11 +67,12 @@ def setup_parser(
             "logs, src, build, and previous tarball."
         ),
     )
+    default_version = get_default_python_version()
     build_subparser.add_argument(
         "--python",
-        default=DEFAULT_PYTHON,
+        default=default_version,
         type=str,
-        help="The python version [default: %(default)s]",
+        help="The python version (e.g., 3.10, 3.13.7) [default: %(default)s]",
     )
     build_subparser.add_argument(
         "--no-cleanup",
@@ -146,27 +152,17 @@ def main(args: argparse.Namespace) -> None:
         print(f"Unsupported platform: {sys.platform}")
         sys.exit(1)
 
-    requested = Version(args.python)
-
-    if requested.micro:
+    try:
+        build_version_str = resolve_python_version(args.python)
+    except RuntimeError as e:
+        print(f"Error: {e}")
         pyversions = python_versions()
-        if requested not in pyversions:
-            print(f"Unknown version {requested}")
-            strversions = "\n".join([str(_) for _ in pyversions])
-            print(f"Known versions are:\n{strversions}")
-            sys.exit(1)
-        build_version = requested
-    else:
-        pyversions = python_versions(args.python)
-        build_version = sorted(list(pyversions.keys()))[-1]
-
-    # print(pyversions)
-    # print(pyversions[0].major)
-    # print(pyversions[0].minor)
-    # print(pyversions[0].micro)
-    # print(pyversions[0].pre)
-    # print(pyversions[0].post)
-    # print(pyversions)
+        strversions = "\n".join([str(_) for _ in pyversions])
+        print(f"Known versions are:\n{strversions}")
+        sys.exit(1)
+
+    build_version = Version(build_version_str)
+    pyversions = python_versions()
     print(f"Build Python {build_version}")
 
     # XXX

relenv/common.py

@@ -40,8 +40,6 @@
 
 MODULE_DIR = pathlib.Path(__file__).resolve().parent
 
-DEFAULT_PYTHON = "3.10.18"
-
 LINUX = "linux"
 WIN32 = "win32"
 DARWIN = "darwin"

relenv/create.py

@@ -23,7 +23,11 @@
     format_shebang,
     relative_interpreter,
 )
-from .pyversions import Version, python_versions
+from .pyversions import (
+    get_default_python_version,
+    python_versions,
+    resolve_python_version,
+)
 
 
 @contextlib.contextmanager
@@ -73,11 +77,12 @@ def setup_parser(
         type=str,
         help="The host architecture [default: %(default)s]",
     )
+    default_version = get_default_python_version()
     subparser.add_argument(
         "--python",
-        default="3.10.17",
+        default=default_version,
         type=str,
-        help="The python version [default: %(default)s]",
+        help="The python version (e.g., 3.10, 3.13.7) [default: %(default)s]",
     )
 
 
@@ -106,8 +111,9 @@ def create(
     else:
         writeto = pathlib.Path(name).resolve()
 
+    # Version should be provided by main(), but handle None just in case
     if version is None:
-        version = "3.10.17"
+        version = get_default_python_version()
 
     if pathlib.Path(writeto).exists():
         raise CreateException("The requested path already exists.")
@@ -253,31 +259,17 @@ def main(args: argparse.Namespace) -> None:
             "Warning: Cross compilation support is experimental and is not fully tested or working!"
         )
 
-    # Resolve version (support minor version like "3.12" or full version like "3.12.7")
-    requested = Version(args.python)
-
-    if requested.micro:
-        # Full version specified (e.g., "3.12.7")
+    try:
+        create_version = resolve_python_version(args.python)
+    except RuntimeError as e:
+        print(f"Error: {e}")
         pyversions = python_versions()
-        if requested not in pyversions:
-            print(f"Unknown version {requested}")
-            strversions = "\n".join([str(_) for _ in pyversions])
-            print(f"Known versions are:\n{strversions}")
-            sys.exit(1)
-        create_version = requested
-    else:
-        # Minor version specified (e.g., "3.12"), resolve to latest
-        pyversions = python_versions(args.python)
-        if not pyversions:
-            print(f"Unknown minor version {requested}")
-            all_versions = python_versions()
-            strversions = "\n".join([str(_) for _ in all_versions])
-            print(f"Known versions are:\n{strversions}")
-            sys.exit(1)
-        create_version = sorted(list(pyversions.keys()))[-1]
+        strversions = "\n".join([str(_) for _ in pyversions])
+        print(f"Known versions are:\n{strversions}")
+        sys.exit(1)
 
     try:
-        create(name, arch=args.arch, version=str(create_version))
+        create(name, arch=args.arch, version=create_version)
     except CreateException as exc:
         print(exc)
         sys.exit(1)

relenv/fetch.py

@@ -16,14 +16,14 @@
 from .common import (
     CHECK_HOSTS,
     DATA_DIR,
-    DEFAULT_PYTHON,
     __version__,
     build_arch,
     check_url,
     download_url,
     get_triplet,
     work_dir,
 )
+from .pyversions import get_default_python_version, resolve_python_version
 
 
 def setup_parser(
@@ -45,11 +45,12 @@ def setup_parser(
         type=str,
         help="Architecture to download. [default: %(default)s]",
     )
+    default_version = get_default_python_version()
     subparser.add_argument(
         "--python",
-        default=DEFAULT_PYTHON,
+        default=default_version,
         type=str,
-        help="The python version [default: %(default)s]",
+        help="The python version (e.g., 3.10, 3.13.7) [default: %(default)s]",
     )
 
 
@@ -87,7 +88,8 @@ def main(args: argparse.Namespace) -> None:
     """
     version = os.environ.get("RELENV_FETCH_VERSION", __version__)
     triplet = get_triplet(machine=args.arch)
-    python = args.python
+    # args.python will be the default version or user-specified version
+    python = resolve_python_version(args.python)
     check_hosts = CHECK_HOSTS
     if os.environ.get("RELENV_FETCH_HOST", ""):
         check_hosts = [os.environ["RELENV_FETCH_HOST"]]

relenv/pyversions.py

@@ -947,6 +947,54 @@ def python_versions(
     return {version: pyversions[str(version)] for version in versions}
 
 
+def get_default_python_version() -> str:
+    """
+    Get the default Python version to use when none is specified.
+
+    :return: The default Python version string (e.g., "3.10.19")
+    """
+    # Default to latest 3.10 version
+    pyversions = python_versions("3.10")
+    if not pyversions:
+        raise RuntimeError("No 3.10 versions found")
+    latest = sorted(list(pyversions.keys()))[-1]
+    return str(latest)
+
+
+def resolve_python_version(version_spec: str | None = None) -> str:
+    """
+    Resolve a Python version specification to a full version string.
+
+    If version_spec is None, returns the latest Python 3.10 version.
+    If version_spec is partial (e.g., "3.10"), returns the latest micro version.
+    If version_spec is full (e.g., "3.10.19"), returns it as-is after validation.
+
+    :param version_spec: Version specification (None, "3.10", or "3.10.19")
+    :return: Full version string (e.g., "3.10.19")
+    :raises RuntimeError: If the version is not found
+    """
+    if version_spec is None:
+        # Default to latest 3.10 version
+        return get_default_python_version()
+
+    requested = Version(version_spec)
+
+    if requested.micro is not None:
+        # Full version specified - validate it exists
+        pyversions = python_versions()
+        if requested not in pyversions:
+            raise RuntimeError(f"Unknown version {requested}")
+        return str(requested)
+    else:
+        # Partial version (major.minor) - get latest micro
+        pyversions = python_versions(version_spec)
+        if not pyversions:
+            raise RuntimeError(f"Unknown minor version {requested}")
+        # Return the latest version for this major.minor
+        latest = sorted(list(pyversions.keys()))[-1]
+        return str(latest)
+
+
 def setup_parser(
     subparsers: argparse._SubParsersAction[argparse.ArgumentParser],
 ) -> None:

tests/test_pyversions_runtime.py

@@ -175,3 +175,80 @@ def fake_fetch(url: str) -> str:
     assert "5.6.3" in versions
     # Verify sorting (latest first)
     assert versions[0] == "5.8.1"
+
+
+def test_resolve_python_version_none_defaults_to_latest_310() -> None:
+    """Test that None resolves to the latest 3.10 version."""
+    result = pyversions.resolve_python_version(None)
+    assert result.startswith("3.10.")
+    # Verify it's a valid version in the registry
+    versions = pyversions.python_versions("3.10")
+    assert pyversions.Version(result) in versions
+    # Verify it's the latest 3.10 version
+    latest = sorted(list(versions.keys()))[-1]
+    assert result == str(latest)
+
+
+def test_resolve_python_version_partial_minor() -> None:
+    """Test that partial versions (3.10) resolve to latest micro."""
+    result = pyversions.resolve_python_version("3.10")
+    assert result.startswith("3.10.")
+    # Verify it resolves to the latest micro version
+    versions = pyversions.python_versions("3.10")
+    latest = sorted(list(versions.keys()))[-1]
+    assert result == str(latest)
+
+
+def test_resolve_python_version_different_minors() -> None:
+    """Test resolution works for different minor versions."""
+    result_311 = pyversions.resolve_python_version("3.11")
+    assert result_311.startswith("3.11.")
+
+    result_313 = pyversions.resolve_python_version("3.13")
+    assert result_313.startswith("3.13.")
+
+    # Verify they're different
+    assert result_311 != result_313
+
+    # Verify each is the latest for its minor version
+    versions_311 = pyversions.python_versions("3.11")
+    latest_311 = sorted(list(versions_311.keys()))[-1]
+    assert result_311 == str(latest_311)
+
+    versions_313 = pyversions.python_versions("3.13")
+    latest_313 = sorted(list(versions_313.keys()))[-1]
+    assert result_313 == str(latest_313)
+
+
+def test_resolve_python_version_full_version() -> None:
+    """Test that full versions are validated and returned as-is."""
+    # Get any valid version from the registry
+    all_versions = pyversions.python_versions()
+    some_version = str(next(iter(all_versions)))
+
+    result = pyversions.resolve_python_version(some_version)
+    assert result == some_version
+
+
+def test_resolve_python_version_invalid_full_version() -> None:
+    """Test that invalid full versions raise RuntimeError."""
+    with pytest.raises(RuntimeError, match="Unknown version"):
+        pyversions.resolve_python_version("3.10.999")
+
+
+def test_resolve_python_version_invalid_minor_version() -> None:
+    """Test that invalid minor versions raise RuntimeError."""
+    with pytest.raises(RuntimeError, match="Unknown minor version"):
+        pyversions.resolve_python_version("3.99")
+
+
+def test_resolve_python_version_consistency() -> None:
+    """Test that resolve_python_version is idempotent for full versions."""
+    # Get a valid full version from the registry
+    all_versions = pyversions.python_versions()
+    some_version = str(next(iter(all_versions)))
+
+    # Resolving a full version twice should give the same result
+    first = pyversions.resolve_python_version(some_version)
+    second = pyversions.resolve_python_version(first)
+    assert first == second