MetaData() crashes in any environment with packaging >= 26.3

pyPRMS/metadata/metadata.py

@@ -117,29 +117,30 @@ def __filter_by_version(self, elem: xmlET.Element, name: str,
 
         meta_dict[name] = {}
 
-        try:
-            var_version = Version(elem.attrib.get('version'))
+        # Missing version/deprecated attributes are checked explicitly:
+        # relying on Version(None) to raise is fragile (packaging < 26.3
+        # raised TypeError, packaging >= 26.3 raises InvalidVersion).
+        version_attr = elem.attrib.get('version')
+        if version_attr is not None:
+            var_version = Version(version_attr)
 
             if var_version > req_version:
                 if self.__verbose:   # pragma: no cover
                     con.print(f'[green]INFO[/]: [bold]{name}[/] requires version {str(var_version)}')
                 del meta_dict[name]
                 return True
             meta_dict[name]['version'] = str(var_version)
-        except TypeError:
-            pass
 
-        try:
-            depr_version = Version(elem.attrib.get('deprecated'))
+        depr_attr = elem.attrib.get('deprecated')
+        if depr_attr is not None:
+            depr_version = Version(depr_attr)
 
             if depr_version <= req_version:
                 if self.__verbose:   # pragma: no cover
                     con.print(f'[green]INFO[/]: [bold]{name}[/] was deprecated at version {str(depr_version)}')
                 del meta_dict[name]
                 return True
             meta_dict[name]['deprecated'] = depr_version
-        except TypeError:
-            pass
 
         return False
 

pyproject.toml

@@ -23,6 +23,7 @@ dependencies = ["cartopy",
     "netCDF4!=1.7.4",
     "networkx>=2",
     "numpy",
+    "packaging",
     "pandas",
     "pyproj",
     "rich",

tests/func/test_MetaData.py

@@ -26,3 +26,16 @@ def test_metadata_version5(self):
     def test_metadata_version4(self):
         prms_meta = MetaData(version='4', verbose=True).metadata
         assert prms_meta['parameters'].get('soilzone_aet_flag', None) is None
+
+    def test_metadata_no_version_attributes(self):
+        """Entries lacking version/deprecated XML attributes are retained.
+
+        Regression test: packaging >= 26.3 raises InvalidVersion instead of
+        TypeError for Version(None), which crashed MetaData for any element
+        without these attributes.
+        """
+        prms_meta = MetaData(version='5.2.1.1', verbose=True).metadata
+        # cascade_flag has neither a version nor a deprecated attribute
+        assert 'cascade_flag' in prms_meta['control']
+        # nhruOutON_OFF has only a deprecated attribute
+        assert 'nhruOutON_OFF' in prms_meta['control']