Adapt Google Cloud CLI to the ruamel.yaml 0.18+ API.
Replace deprecated module-level YAML loading and dumping functions with
the YAML() instance API. Preserve safe and round-trip processing, YAML
version selection, formatting options, and custom tag handling.
Required for compatibility with system-installed dev-python/ruamel-yaml
when unbundling Google Cloud CLI's vendored Python dependencies.
--- ../lib/googlecloudsdk/calliope/command_loading.py	2026-10-16 19:33:45.750683070 +0300
+++ ../lib/googlecloudsdk/calliope/command_loading.py	2026-10-16 19:34:08.436778266 +0300
@@ -210,8 +210,8 @@
 
 @Cache
 def _SafeLoadYamlFile(path):
-  return yaml.safe_load(pkg_resources.GetResourceFromFile(path))
-
+  return yaml.YAML(typ='safe', pure=True).load(
+      pkg_resources.GetResourceFromFile(path))
 
 @Cache
 def _CustomLoadYamlFile(path):
--- ../lib/googlecloudsdk/calliope/base.py	2026-10-16 22:25:56.083546610 +0300
+++ ../lib/googlecloudsdk/calliope/base.py	2026-10-16 22:26:34.813923975 +0300
@@ -630,13 +630,10 @@
       try:
         from ruamel import yaml as ruamel_yaml  # pylint: disable=g-import-not-at-top
 
-        class _SidecarSafeLoader(ruamel_yaml.SafeLoader):
-          pass
-
-        _SidecarSafeLoader.add_multi_constructor(
-            '!', lambda loader, tag, node: None
-        )
-        data = ruamel_yaml.load(content, _SidecarSafeLoader)
+        parser = ruamel_yaml.YAML(typ='safe', pure=True)
+        parser.constructor.add_multi_constructor(
+            '!', lambda constructor, tag, node: None)
+        data = parser.load(content)
       except Exception:  # pylint: disable=broad-except
         return []
     except Exception:  # pylint: disable=broad-except
--- ../lib/googlecloudsdk/core/yaml.py	2026-10-16 22:14:21.267817424 +0300
+++ ../lib/googlecloudsdk/core/yaml.py	2026-10-16 22:25:38.806967004 +0300
@@ -23,6 +23,7 @@
 
 
 import collections
+import io
 
 from googlecloudsdk.core import exceptions
 from googlecloudsdk.core import yaml_location_value
@@ -57,6 +58,46 @@
     Dumper=yaml.dumper.RoundTripDumper)
 
 
+def _NewYAML(round_trip=False, version=None, preserve_quotes=None):
+  parser = yaml.YAML(typ='rt' if round_trip else 'safe', pure=True)
+  if version is not None:
+    parser.version = tuple(int(part) for part in version.split('.'))
+  if preserve_quotes is not None:
+    parser.preserve_quotes = preserve_quotes
+  parser.default_flow_style = False
+  parser.indent(mapping=2, sequence=2, offset=0)
+  parser.representer.add_representer(
+      collections.OrderedDict, parser.representer.represent_dict)
+  if round_trip:
+    parser.representer.add_representer(
+        type(None),
+        lambda representer, value: representer.represent_scalar(
+            'tag:yaml.org,2002:null', 'null'))
+  return parser
+
+
+def _DumpYAML(data, stream=None, round_trip=False, multiple=False, **kwargs):
+  parser = _NewYAML(round_trip=round_trip, version=VERSION_1_2)
+  options = {
+      'default_flow_style': 'default_flow_style',
+      'explicit_start': 'explicit_start',
+      'explicit_end': 'explicit_end',
+      'allow_unicode': 'allow_unicode',
+      'width': 'width',
+  }
+  for key, attribute in options.items():
+    if key in kwargs:
+      setattr(parser, attribute, kwargs.pop(key))
+  if kwargs:
+    raise TypeError('Unsupported YAML dump options: {}'.format(kwargs))
+
+  output = io.StringIO() if stream is None else stream
+  if multiple:
+    parser.dump_all(data, output)
+  else:
+    parser.dump(data, output)
+  return output.getvalue() if stream is None else None
+
 # Always output None as "null", instead of just empty.
 yaml.add_representer(
     type(None),
@@ -133,10 +174,11 @@
   try:
     if location_value:
       return yaml_location_value.LocationValueLoad(stream)
-    loader = yaml.RoundTripLoader if round_trip else yaml.SafeLoader
-    return yaml.load(
-        stream, loader, version=version, preserve_quotes=preserve_quotes
-    )
+    parser = _NewYAML(
+        round_trip=round_trip,
+        version=version,
+        preserve_quotes=preserve_quotes)
+    return parser.load(stream)
   except yaml.YAMLError as e:
     raise YAMLParseError(e, f=file_hint)
 
@@ -158,9 +200,9 @@
   Yields:
     The parsed YAML data.
   """
-  loader = yaml.RoundTripLoader if round_trip else yaml.SafeLoader
   try:
-    for x in yaml.load_all(stream, loader, version=version):
+    parser = _NewYAML(round_trip=round_trip, version=version)
+    for x in parser.load_all(stream):
       yield x
   except yaml.YAMLError as e:
     raise YAMLParseError(e, f=file_hint)
@@ -249,9 +291,8 @@
   Returns:
     The string representation of the YAML data if stream is None.
   """
-  method = yaml.round_trip_dump if round_trip else yaml.safe_dump
-  return method(data, stream=stream, default_flow_style=False, indent=2,
-                **kwargs)
+  return _DumpYAML(
+      data, stream=stream, round_trip=round_trip, **kwargs)
 
 
 def dump_all(documents, stream=None, **kwargs):
@@ -265,8 +306,8 @@
   Returns:
     The string representation of the YAML data if stream is None.
   """
-  return yaml.safe_dump_all(
-      documents, stream=stream, default_flow_style=False, indent=2, **kwargs)
+  return _DumpYAML(
+      documents, stream=stream, multiple=True, **kwargs)
 
 
 def dump_all_round_trip(documents, stream=None, **kwargs):
@@ -280,9 +321,8 @@
   Returns:
     The string representation of the YAML data if stream is None.
   """
-  return yaml.dump_all(
-      documents, stream=stream, default_flow_style=False, indent=2,
-      Dumper=yaml.RoundTripDumper, **kwargs)
+  return _DumpYAML(
+      documents, stream=stream, round_trip=True, multiple=True, **kwargs)
 
 
 def convert_to_block_text(data):