Fix CLI crashing on every invocation when package metadata is missing

osipy/cli/main.py

@@ -31,9 +31,9 @@
 
 def _get_version() -> str:
     """Read version without importing the full osipy package."""
-    from importlib.metadata import version
+    from osipy._version import __version__
 
-    return version("osipy")
+    return __version__
 
 
 def create_parser() -> argparse.ArgumentParser:

tests/unit/cli/test_config.py

@@ -26,7 +26,7 @@
     dump_defaults,
     load_config,
 )
-from osipy.cli.main import create_parser
+from osipy.cli.main import _get_version, create_parser
 
 # ---------------------------------------------------------------------------
 # Fixtures
@@ -1114,3 +1114,26 @@ def test_output_override(self) -> None:
 
         args_short = parser.parse_args(["-o", "/out", "config.yaml", "/data"])
         assert args_short.output == "/out"
+
+
+# ---------------------------------------------------------------------------
+# TestVersionLookup — GH-173
+# ---------------------------------------------------------------------------
+
+
+class TestVersionLookup:
+    """create_parser() must never crash reading the version, since it runs
+    on every CLI invocation, not just `--version`."""
+
+    def test_get_version_matches_version_module(self) -> None:
+        """_get_version() reads straight from osipy._version."""
+        from osipy._version import __version__
+
+        assert _get_version() == __version__
+
+    def test_version_flag_exits_cleanly(self) -> None:
+        """--version exits 0 without raising."""
+        parser = create_parser()
+        with pytest.raises(SystemExit) as exc_info:
+            parser.parse_args(["--version"])
+        assert exc_info.value.code == 0