Perhaps it is useful with a debug mode (-d ?) but it should output all this stuff for normal users.

======================================================================
ERROR: testActualSchemaAgainstReadme (cros_config_host.generate_schema_doc_unittest.SchemaTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/mnt/host/source/src/platform2/chromeos-config/cros_config_host/generate_schema_doc_unittest.py", line 25, in testActualSchemaAgainstReadme
    output)
  File "/mnt/host/source/src/platform2/chromeos-config/cros_config_host/generate_schema_doc.py", line 101, in Main
    schema_yaml = yaml.load(schema_stream.read())
  File "/usr/lib64/python2.7/site-packages/yaml/__init__.py", line 71, in load
    return loader.get_single_data()
  File "/usr/lib64/python2.7/site-packages/yaml/constructor.py", line 37, in get_single_data
    node = self.get_single_node()
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 36, in get_single_node
    document = self.compose_document()
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib64/python2.7/site-packages/yaml/composer.py", line 127, in compose_mapping_node
    while not self.check_event(MappingEndEvent):
  File "/usr/lib64/python2.7/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
  File "/usr/lib64/python2.7/site-packages/yaml/parser.py", line 428, in parse_block_mapping_key
    if self.check_token(KeyToken):
  File "/usr/lib64/python2.7/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/usr/lib64/python2.7/site-packages/yaml/scanner.py", line 220, in fetch_more_tokens
    return self.fetch_value()
  File "/usr/lib64/python2.7/site-packages/yaml/scanner.py", line 580, in fetch_value
    self.get_mark())
ScannerError: mapping values are not allowed here
  in "<string>", line 258, column 35:
                          type: string:
                                      ^