# YAML Test Matrix

--- &test-4EJS
  Title: Invalid tabs as indendation in a mapping
  Tags: [ error, mapping, whitespace ]

YAML

---
a:
	b:
		c: value

Expected Events

+STR
+DOC ---
+MAP
=VAL :a

Expected JSON



nim-nimyaml-event

 invalid_incorrect
+STR
+DOC ---
+MAP
=VAL :a
=VAL :
=VAL :b
=VAL :
=VAL :c
=VAL :value
-MAP
-DOC
-STR

perl-tiny-json

 invalid_incorrect
{
   "a" : {
      "b" : {
         "c" : "value"
      }
   }
}

perl-tiny-perl

 invalid_incorrect
{
  'a' => {
           'b' => {
                    'c' => 'value'
                  }
         }
}

c-libfyaml-event

 invalid_correct
stdin:3:1: error: invalid tab as indendation in a mapping
	b:
^~~~~~~~
[NOT]: fy_fetch_plain_scalar() failed
[NOT]: fy_fetch_tokens() failed
[NOT]: failed to peek token
+STR
+DOC ---
+MAP
=VAL :a

c-libfyaml-json

 invalid_correct
stdin:3:1: error: invalid tab as indendation in a mapping
	b:
^~~~~~~~
[NOT]: fy_fetch_plain_scalar() failed
[NOT]: fy_fetch_tokens() failed
[NOT]: failed to peek token

c-libyaml-event

 invalid_correct
Parse error: found character that cannot start any token
+STR
+DOC ---
+MAP
=VAL :a

cpp-yamlcpp-event

 invalid_correct
Exception:
yaml-cpp: error at line 3, column 3: illegal map value
+STR
+DOC
+MAP
=VAL :a
=VAL :b

dotnet-yamldotnet-event

 invalid_correct
Unhandled exception. YamlDotNet.Core.SyntaxErrorException: (Line: 1, Col: 1, Idx: 0) - (Line: 1, Col: 1, Idx: 0): While scanning a mapping, found invalid tab as indentation.
   at YamlDotNet.Core.Scanner.FetchNextToken()
   at YamlDotNet.Core.Scanner.FetchMoreTokens()
   at YamlDotNet.Core.Scanner.MoveNextWithoutConsuming()
   at YamlDotNet.Core.Parser.GetCurrentToken()
   at YamlDotNet.Core.Parser.ParseBlockMappingValue()
   at YamlDotNet.Core.Parser.StateMachine()
   at YamlDotNet.Core.Parser.MoveNext()
   at YamlDotNet.RepresentationModel.LibYamlEventStream.WriteTo(TextWriter textWriter)
   at Program.Main(String[] commandLineArguments)
Aborted (core dumped)
+STR
+DOC ---
+MAP
=VAL :a

dotnet-yamldotnet-json

 invalid_correct
Unhandled exception. YamlDotNet.Core.SyntaxErrorException: (Line: 1, Col: 1, Idx: 0) - (Line: 1, Col: 1, Idx: 0): While scanning a mapping, found invalid tab as indentation.
   at YamlDotNet.Core.Scanner.FetchNextToken()
   at YamlDotNet.Core.Scanner.FetchMoreTokens()
   at YamlDotNet.Core.Scanner.MoveNextWithoutConsuming()
   at YamlDotNet.Core.Parser.GetCurrentToken()
   at YamlDotNet.Core.Parser.ParseBlockMappingValue()
   at YamlDotNet.Core.Parser.StateMachine()
   at YamlDotNet.Core.Parser.MoveNext()
   at YamlDotNet.Core.ParserExtensions.TryConsume[T](IParser parser, T& event)
   at YamlDotNet.Serialization.NodeDeserializers.ScalarNodeDeserializer.YamlDotNet.Serialization.INodeDeserializer.Deserialize(IParser parser, Type expectedType, Func`3 nestedObjectDeserializer, Object& value)
   at YamlDotNet.Serialization.ValueDeserializers.NodeValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.ValueDeserializers.AliasValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.ValueDeserializers.NodeValueDeserializer.<>c__DisplayClass3_0.<DeserializeValue>b__0(IParser r, Type t)
   at YamlDotNet.Serialization.NodeDeserializers.DictionaryNodeDeserializer.DeserializeHelper(Type tKey, Type tValue, IParser parser, Func`3 nestedObjectDeserializer, IDictionary result)
   at YamlDotNet.Serialization.NodeDeserializers.DictionaryNodeDeserializer.YamlDotNet.Serialization.INodeDeserializer.Deserialize(IParser parser, Type expectedType, Func`3 nestedObjectDeserializer, Object& value)
   at YamlDotNet.Serialization.ValueDeserializers.NodeValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.ValueDeserializers.AliasValueDeserializer.DeserializeValue(IParser parser, Type expectedType, SerializerState state, IValueDeserializer nestedObjectDeserializer)
   at YamlDotNet.Serialization.Deserializer.Deserialize(IParser parser, Type type)
   at YamlDotNet.Serialization.Deserializer.Deserialize(TextReader input, Type type)
   at YamlDotNet.Serialization.Deserializer.Deserialize(TextReader input)
   at Program.Main(String[] commandLineArguments)
Aborted (core dumped)

hs-hsyaml-event

 invalid_correct
Parsing error near byte offset Pos {posByteOffset = 7, posCharOffset = 7, posLine = 3, posColumn = 0} (Unexpected '	')
+STR
+DOC ---
+MAP
=VAL :a
=VAL :
-MAP
-DOC

hs-hsyaml-json

 invalid_correct
hsyaml-parser: user error (Unexpected '	')

java-snakeyaml-event

 invalid_correct
Exception in thread "main" while scanning for the next token
found character '\t(TAB)' that cannot start any token. (Do not use \t(TAB) for indentation)
 in 'reader', line 3, column 1:
    	b:
    ^

	at org.yaml.snakeyaml.scanner.ScannerImpl.fetchMoreTokens(ScannerImpl.java:439)
	at org.yaml.snakeyaml.scanner.ScannerImpl.checkToken(ScannerImpl.java:248)
	at org.yaml.snakeyaml.parser.ParserImpl$ParseBlockMappingValue.produce(ParserImpl.java:665)
	at org.yaml.snakeyaml.parser.ParserImpl.peekEvent(ParserImpl.java:165)
	at org.yaml.snakeyaml.Yaml$3.hasNext(Yaml.java:677)
	at org.yaml.editor.Snake2Events.yamlToEvents(Snake2Events.java:111)
	at org.yaml.editor.Snake2Events.main(Snake2Events.java:119)

java-snakeyaml-json

 invalid_correct
Exception in thread "main" while scanning for the next token
found character '\t(TAB)' that cannot start any token. (Do not use \t(TAB) for indentation)
 in 'reader', line 3, column 1:
    	b:
    ^

	at org.yaml.snakeyaml.scanner.ScannerImpl.fetchMoreTokens(ScannerImpl.java:439)
	at org.yaml.snakeyaml.scanner.ScannerImpl.checkToken(ScannerImpl.java:248)
	at org.yaml.snakeyaml.parser.ParserImpl$ParseBlockMappingValue.produce(ParserImpl.java:665)
	at org.yaml.snakeyaml.parser.ParserImpl.peekEvent(ParserImpl.java:165)
	at org.yaml.snakeyaml.comments.CommentEventsCollector$1.peek(CommentEventsCollector.java:59)
	at org.yaml.snakeyaml.comments.CommentEventsCollector$1.peek(CommentEventsCollector.java:45)
	at org.yaml.snakeyaml.comments.CommentEventsCollector.collectEvents(CommentEventsCollector.java:140)
	at org.yaml.snakeyaml.comments.CommentEventsCollector.collectEvents(CommentEventsCollector.java:119)
	at org.yaml.snakeyaml.composer.Composer.composeScalarNode(Composer.java:214)
	at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:184)
	at org.yaml.snakeyaml.composer.Composer.composeKeyNode(Composer.java:310)
	at org.yaml.snakeyaml.composer.Composer.composeMappingChildren(Composer.java:301)
	at org.yaml.snakeyaml.composer.Composer.composeMappingNode(Composer.java:286)
	at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:188)
	at org.yaml.snakeyaml.composer.Composer.getNode(Composer.java:115)
	at org.yaml.snakeyaml.constructor.BaseConstructor.getData(BaseConstructor.java:135)
	at org.yaml.snakeyaml.Yaml$1.next(Yaml.java:514)
	at org.yaml.editor.Snake2Json.yamlToJson(Snake2Json.java:18)
	at org.yaml.editor.Snake2Json.main(Snake2Json.java:25)

js-jsyaml-json

 invalid_correct
/node/node_modules/js-yaml/lib/loader.js:187
  throw generateError(state, message);
  ^
YAMLException: tab characters must not be used in indentation (3:1)

 1 | ---
 2 | a:
 3 | →b:
-----^
 4 | →→c: value
    at generateError (/node/node_modules/js-yaml/lib/loader.js:183:10)
    at throwError (/node/node_modules/js-yaml/lib/loader.js:187:9)
    at readBlockMapping (/node/node_modules/js-yaml/lib/loader.js:1062:7)
    at composeNode (/node/node_modules/js-yaml/lib/loader.js:1441:12)
    at readDocument (/node/node_modules/js-yaml/lib/loader.js:1625:3)
    at loadDocuments (/node/node_modules/js-yaml/lib/loader.js:1688:5)
    at Object.loadAll (/node/node_modules/js-yaml/lib/loader.js:1701:19)
    at Object.<anonymous> (/yaml/bin/js-jsyaml-json:7:13)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)

js-yaml-event

 invalid_correct
Tabs are not allowed as indentation at line 3, column 1:

a:
	b:
^
+STR
+DOC ---
+MAP
=VAL :a
=VAL :

js-yaml-json

 invalid_correct
/yaml/bin/js-yaml-json:8
  if (doc.errors.length !== 0) throw doc.errors[0]
                               ^

YAMLParseError: Tabs are not allowed as indentation at line 3, column 1:

a:
	b:
^

    at Composer.onError (/node/node_modules/yaml/dist/compose/composer.js:71:34)
    at Object.resolveProps (/node/node_modules/yaml/dist/compose/resolve-props.js:33:21)
    at Object.resolveBlockMap (/node/node_modules/yaml/dist/compose/resolve-block-map.js:55:41)
    at Object.composeCollection (/node/node_modules/yaml/dist/compose/compose-collection.js:13:36)
    at Object.composeNode (/node/node_modules/yaml/dist/compose/compose-node.js:30:38)
    at Object.composeDoc (/node/node_modules/yaml/dist/compose/compose-doc.js:31:23)
    at Composer.next (/node/node_modules/yaml/dist/compose/composer.js:152:40)
    at next (<anonymous>)
    at Composer.compose (/node/node_modules/yaml/dist/compose/composer.js:134:25)
    at compose.next (<anonymous>)

lua-lyaml-json

 invalid_correct
luajit: 2:1: found character that cannot start any token
stack traceback:
	[C]: in function 'error'
	/usr/local/share/lua/5.1/lyaml/init.lua:306: in function 'error'
	/usr/local/share/lua/5.1/lyaml/init.lua:325: in function 'parse'
	/usr/local/share/lua/5.1/lyaml/init.lua:443: in function 'load_node'
	/usr/local/share/lua/5.1/lyaml/init.lua:378: in function 'load_node'
	/usr/local/share/lua/5.1/lyaml/init.lua:497: in function 'load'
	/yaml/bin/lua-lyaml-json:6: in main chunk
	[C]: at 0x5611009f4f97

perl-pp-event

 invalid_correct
Line      : 3
Column    : 1
Expected  : ALIAS COLON DOC_END DOC_START EOL PLAIN QUESTION QUOTED
Got       : WS
Where     : /perl5/lib/perl5/YAML/PP/Parser.pm line 392
YAML      : "\tb:\n"
  at /yaml/bin/perl-pp-event line 25.
+STR
+DOC ---
+MAP
=VAL :a
=VAL :

perl-pp-json

 invalid_correct
Line      : 3
Column    : 1
Expected  : ALIAS COLON DOC_END DOC_START EOL PLAIN QUESTION QUOTED
Got       : WS
Where     : /perl5/lib/perl5/YAML/PP/Parser.pm line 392
YAML      : "\tb:\n"
  at /perl5/lib/perl5/YAML/PP/Loader.pm line 94.

perl-pp-perl

 invalid_correct
Line      : 3
Column    : 1
Expected  : ALIAS COLON DOC_END DOC_START EOL PLAIN QUESTION QUOTED
Got       : WS
Where     : /perl5/lib/perl5/YAML/PP/Parser.pm line 392
YAML      : "\tb:\n"
  at /perl5/lib/perl5/YAML/PP/Loader.pm line 94.

perl-pplibyaml-event

 invalid_correct
YAML::PP::LibYAML Error: The problem:

    found character that cannot start any token

was found at , line: 3, column: 1
while scanning for the next token at line: 3, column: 1

perl-pplibyaml-json

 invalid_correct
YAML::PP::LibYAML Error: The problem:

    found character that cannot start any token

was found at , line: 3, column: 1
while scanning for the next token at line: 3, column: 1

perl-pplibyaml-perl

 invalid_correct
YAML::PP::LibYAML Error: The problem:

    found character that cannot start any token

was found at , line: 3, column: 1
while scanning for the next token at line: 3, column: 1

perl-refparser-event

 invalid_correct
Parser finished before end of input at /perl5/lib/perl5/YAML/Parser.pm line 4047, <> line 1.

perl-syck-json

 invalid_correct
Syck parser (line 3, column 3): syntax error at /perl5/lib/perl5/x86_64-linux-thread-multi/YAML/Syck.pm line 60, <> line 1.

perl-syck-perl

 invalid_correct
Syck parser (line 3, column 3): syntax error at /perl5/lib/perl5/x86_64-linux-thread-multi/YAML/Syck.pm line 60, <> line 1.

perl-xs-json

 invalid_correct
YAML::XS::Load Error: The problem:

    found character that cannot start any token

was found at document: 1, line: 3, column: 1
while scanning for the next token at line: 3, column: 1

perl-xs-perl

 invalid_correct
YAML::XS::Load Error: The problem:

    found character that cannot start any token

was found at document: 1, line: 3, column: 1
while scanning for the next token at line: 3, column: 1

perl-yaml-json

 invalid_correct
YAML Error: YAML_PARSE_ERR_NONSPACE_INDENTATION
   Code: YAML_PARSE_ERR_NONSPACE_INDENTATION
   Line: 3
   Document: 1
 at /perl5/lib/perl5/YAML/Loader.pm line 748.

perl-yaml-perl

 invalid_correct
YAML Error: YAML_PARSE_ERR_NONSPACE_INDENTATION
   Code: YAML_PARSE_ERR_NONSPACE_INDENTATION
   Line: 3
   Document: 1
 at /perl5/lib/perl5/YAML/Loader.pm line 748.

py-pyyaml-event

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-pyyaml-event", line 7, in <module>
    for event in yaml.parse(sys.stdin.read()):
  File "/python/lib/python3.7/site-packages/yaml/__init__.py", line 75, in parse
    while loader.check_event():
  File "/python/lib/python3.7/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
  File "/python/lib/python3.7/site-packages/yaml/parser.py", line 449, in parse_block_mapping_value
    if not self.check_token(KeyToken, ValueToken, BlockEndToken):
  File "/python/lib/python3.7/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.7/site-packages/yaml/scanner.py", line 260, in fetch_more_tokens
    self.get_mark())
yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 3, column 1:
    	b:
    ^
+STR
+DOC ---
+MAP
=VAL :a

py-pyyaml-json

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-pyyaml-json", line 19, in <module>
    for doc in yaml.load_all(sys.stdin.read(), Loader=yaml.FullLoader):
  File "/python/lib/python3.7/site-packages/yaml/__init__.py", line 130, in load_all
    yield loader.get_data()
  File "/python/lib/python3.7/site-packages/yaml/constructor.py", line 45, in get_data
    return self.construct_document(self.get_node())
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 27, in get_node
    return self.compose_document()
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 64, in compose_node
    if self.check_event(AliasEvent):
  File "/python/lib/python3.7/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
  File "/python/lib/python3.7/site-packages/yaml/parser.py", line 449, in parse_block_mapping_value
    if not self.check_token(KeyToken, ValueToken, BlockEndToken):
  File "/python/lib/python3.7/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.7/site-packages/yaml/scanner.py", line 260, in fetch_more_tokens
    self.get_mark())
yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 3, column 1:
    	b:
    ^

py-pyyaml-py

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-pyyaml-py", line 36, in <module>
    for doc in yaml.load_all(sys.stdin.read(), Loader=yaml.FullLoader):
  File "/python/lib/python3.7/site-packages/yaml/__init__.py", line 130, in load_all
    yield loader.get_data()
  File "/python/lib/python3.7/site-packages/yaml/constructor.py", line 45, in get_data
    return self.construct_document(self.get_node())
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 27, in get_node
    return self.compose_document()
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 133, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/python/lib/python3.7/site-packages/yaml/composer.py", line 64, in compose_node
    if self.check_event(AliasEvent):
  File "/python/lib/python3.7/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
  File "/python/lib/python3.7/site-packages/yaml/parser.py", line 449, in parse_block_mapping_value
    if not self.check_token(KeyToken, ValueToken, BlockEndToken):
  File "/python/lib/python3.7/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.7/site-packages/yaml/scanner.py", line 260, in fetch_more_tokens
    self.get_mark())
yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 3, column 1:
    	b:
    ^

py-ruamel-event

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-event", line 7, in <module>
    for event in ruamel.yaml.parse(sys.stdin.read()):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/main.py", line 907, in parse
    while loader._parser.check_event():
  File "/python/lib/python3.7/site-packages/ruamel/yaml/parser.py", line 140, in check_event
    self.current_event = self.state()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/parser.py", line 603, in parse_block_mapping_value
    if self.scanner.check_token(ValueToken):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/scanner.py", line 322, in fetch_more_tokens
    self.reader.get_mark(),
ruamel.yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 3, column 1:
    	b:
    ^ (line: 3)
+STR
+DOC ---
+MAP
=VAL :a

py-ruamel-json

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-json", line 19, in <module>
    for doc in ruamel.yaml.load_all(sys.stdin.read(), Loader=ruamel.yaml.Loader):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/main.py", line 976, in load_all
    yield loader._constructor.get_data()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/constructor.py", line 106, in get_data
    return self.construct_document(self.composer.get_node())
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 68, in get_node
    return self.compose_document()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 101, in compose_document
    node = self.compose_node(None, None)
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 138, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 218, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 111, in compose_node
    if self.parser.check_event(AliasEvent):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/parser.py", line 140, in check_event
    self.current_event = self.state()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/parser.py", line 603, in parse_block_mapping_value
    if self.scanner.check_token(ValueToken):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/scanner.py", line 322, in fetch_more_tokens
    self.reader.get_mark(),
ruamel.yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 3, column 1:
    	b:
    ^ (line: 3)

py-ruamel-py

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-py", line 36, in <module>
    for doc in ruamel.yaml.load_all(sys.stdin.read(), Loader=ruamel.yaml.Loader):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/main.py", line 976, in load_all
    yield loader._constructor.get_data()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/constructor.py", line 106, in get_data
    return self.construct_document(self.composer.get_node())
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 68, in get_node
    return self.compose_document()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 101, in compose_document
    node = self.compose_node(None, None)
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 138, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 218, in compose_mapping_node
    item_value = self.compose_node(node, item_key)
  File "/python/lib/python3.7/site-packages/ruamel/yaml/composer.py", line 111, in compose_node
    if self.parser.check_event(AliasEvent):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/parser.py", line 140, in check_event
    self.current_event = self.state()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/parser.py", line 603, in parse_block_mapping_value
    if self.scanner.check_token(ValueToken):
  File "/python/lib/python3.7/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.7/site-packages/ruamel/yaml/scanner.py", line 322, in fetch_more_tokens
    self.reader.get_mark(),
ruamel.yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 3, column 1:
    	b:
    ^ (line: 3)

ruby-psych-json

 invalid_correct
/usr/lib/ruby/2.5.0/psych.rb:405:in `parse': (<unknown>): found character that cannot start any token while scanning for the next token at line 3 column 1 (Psych::SyntaxError)
	from /usr/lib/ruby/2.5.0/psych.rb:405:in `parse_stream'
	from /usr/lib/ruby/2.5.0/psych.rb:488:in `load_stream'
	from /yaml/bin/ruby-psych-json:6:in `<main>'