# YAML Test Matrix

--- &test-2G84:00
  Title: Literal modifers
  Tags: [ literal, scalar ]

YAML

--- |0

Expected Events

+STR
+DOC ---

Expected JSON



cpp-rapidyaml-event

 invalid_incorrect
+STR
+DOC ---
=VAL '
-DOC
-STR

hs-reference-yeast

 invalid_incorrect
Line  Col Char Byte Token|Content
   1    0    0    0 +DOC |
   1    0    0    0 =HEAD|---
   1    3    3    3 +NODE|
   1    3    3    3 +VAL |
   1    3    3    3 -VAL |
   1    3    3    3 -NODE|
   1    3    3    3 =REST|.|0
   1    6    6    6 =REST|\x0a
   2    0    7    7 -DOC |

perl-syck-json

 invalid_incorrect
""

perl-syck-perl

 invalid_incorrect
''

perl-yaml-json

 invalid_incorrect
"\n"

perl-yaml-perl

 invalid_incorrect
'
'

c-libfyaml-event

 invalid_correct
[ERR]: indentation indicator 0
+STR
+DOC ---

c-libfyaml-json

 invalid_correct
[ERR]: indentation indicator 0

c-libyaml-event

 invalid_correct
Parse error: found an indentation indicator equal to 0
+STR
+DOC ---

cpp-yamlcpp-event

 invalid_correct
Exception:
yaml-cpp: error at line 1, column 7: cannot set zero indentation for a block scalar
+STR
+DOC

dotnet-yamldotnet-event

 invalid_correct
Unhandled exception. YamlDotNet.Core.SyntaxErrorException: (Line: 1, Col: 5, Idx: 4) - (Line: 1, Col: 6, Idx: 5): While scanning a block scalar, found an indentation indicator equal to 0.
   at YamlDotNet.Core.Scanner.ScanBlockScalar(Boolean isLiteral)
   at YamlDotNet.Core.Scanner.FetchBlockScalar(Boolean isLiteral)
   at YamlDotNet.Core.Scanner.FetchNextToken()
   at YamlDotNet.Core.Scanner.FetchMoreTokens()
   at YamlDotNet.Core.Scanner.MoveNextWithoutConsuming()
   at YamlDotNet.Core.Parser.GetCurrentToken()
   at YamlDotNet.Core.Parser.ParseDocumentContent()
   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 ---

dotnet-yamldotnet-json

 invalid_correct
Unhandled exception. YamlDotNet.Core.SyntaxErrorException: (Line: 1, Col: 5, Idx: 4) - (Line: 1, Col: 6, Idx: 5): While scanning a block scalar, found an indentation indicator equal to 0.
   at YamlDotNet.Core.Scanner.ScanBlockScalar(Boolean isLiteral)
   at YamlDotNet.Core.Scanner.FetchBlockScalar(Boolean isLiteral)
   at YamlDotNet.Core.Scanner.FetchNextToken()
   at YamlDotNet.Core.Scanner.FetchMoreTokens()
   at YamlDotNet.Core.Scanner.MoveNextWithoutConsuming()
   at YamlDotNet.Core.Parser.GetCurrentToken()
   at YamlDotNet.Core.Parser.ParseDocumentContent()
   at YamlDotNet.Core.Parser.StateMachine()
   at YamlDotNet.Core.Parser.MoveNext()
   at YamlDotNet.Core.ParserExtensions.TryConsume[T](IParser parser, T& event)
   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)

go-yaml-json

 invalid_correct
yaml: found an indentation indicator equal to 0

hs-hsyaml-event

 invalid_correct
Parsing error near byte offset Pos {posByteOffset = 3, posCharOffset = 3, posLine = 1, posColumn = 3} (Lexical error near " |0")
+STR
+DOC ---
=VAL :

hs-hsyaml-json

 invalid_correct
hsyaml-parser: user error (Lexical error near " |0")

js-jsyaml-json

 invalid_correct
/node/node_modules/js-yaml/lib/loader.js:187
  throw generateError(state, message);
  ^
YAMLException: bad explicit indentation width of a block scalar; it cannot be less than one (1:6)

 1 | --- |0
----------^
    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 readBlockScalar (/node/node_modules/js-yaml/lib/loader.js:855:9)
    at composeNode (/node/node_modules/js-yaml/lib/loader.js:1445:35)
    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 (node:internal/modules/cjs/loader:1358:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1416:10) {
  reason: 'bad explicit indentation width of a block scalar; it cannot be less than one',
  mark: {
    name: null,
    buffer: '--- |0\n',
    position: 5,
    line: 0,
    column: 5,
    snippet: ' 1 | --- |0\n----------^'
  }
}

Node.js v20.13.1

js-yaml-event

 invalid_correct
Block scalar header includes extra characters: |0 at line 1, column 6:

--- |0
     ^
+STR
+DOC ---
=VAL |
-DOC
-STR

js-yaml-json

 invalid_correct
/yaml/bin/js-yaml-json:9
    if (doc.errors.length !== 0) throw doc.errors[0]
                                 ^

YAMLParseError: Block scalar header includes extra characters: |0 at line 1, column 6:

--- |0
     ^

    at Composer.onError (/node/node_modules/yaml/dist/compose/composer.js:69:34)
    at parseBlockScalarHeader (/node/node_modules/yaml/dist/compose/resolve-block-scalar.js:149:9)
    at Object.resolveBlockScalar (/node/node_modules/yaml/dist/compose/resolve-block-scalar.js:7:20)
    at Object.composeScalar (/node/node_modules/yaml/dist/compose/compose-scalar.js:10:30)
    at Object.composeNode (/node/node_modules/yaml/dist/compose/compose-node.js:24:34)
    at Object.composeDoc (/node/node_modules/yaml/dist/compose/compose-doc.js:34:23)
    at Composer.next (/node/node_modules/yaml/dist/compose/composer.js:149:40)
    at next (<anonymous>)
    at Composer.compose (/node/node_modules/yaml/dist/compose/composer.js:131:25)
    at compose.next (<anonymous>) {
  code: 'UNEXPECTED_TOKEN',
  pos: [ 5, 6 ],
  linePos: [ { line: 1, col: 6 }, { line: 1, col: 7 } ]
}

Node.js v20.13.1

lua-lyaml-json

 invalid_correct
luajit: 1:1: found an indentation indicator equal to 0
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:497: in function 'load'
	/yaml/bin/lua-lyaml-json:6: in main chunk
	[C]: at 0x561c44ddbed0

nim-nimyaml-event

 invalid_correct
/tmp/NimYAML-0.16.0/yaml/stream.nim(134) nimyaml_event
/tmp/NimYAML-0.16.0/yaml/stream.nim(106) next
Error: unhandled exception: Illegal character in block scalar header: "0" [YamlStreamError]
+STR

perl-pp-event

 invalid_correct
Line      : 1
Column    : 6
Message   : Invalid block scalar
Where     : /perl5/lib/perl5/YAML/PP/Lexer.pm line 556
YAML      : 0
  at /yaml/bin/perl-pp-event line 46.
+STR
+DOC ---

perl-pp-json

 invalid_correct
Line      : 1
Column    : 6
Message   : Invalid block scalar
Where     : /perl5/lib/perl5/YAML/PP/Lexer.pm line 556
YAML      : 0
  at /perl5/lib/perl5/YAML/PP/Loader.pm line 94.

perl-pp-perl

 invalid_correct
Line      : 1
Column    : 6
Message   : Invalid block scalar
Where     : /perl5/lib/perl5/YAML/PP/Lexer.pm line 556
YAML      : 0
  at /perl5/lib/perl5/YAML/PP/Loader.pm line 94.

perl-pplibyaml-json

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

    found an indentation indicator equal to 0

was found at , line: 1, column: 6
while scanning a block scalar at line: 1, column: 5

perl-pplibyaml-perl

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

    found an indentation indicator equal to 0

was found at , line: 1, column: 6
while scanning a block scalar at line: 1, column: 5

perl-refparser-event

 invalid_correct
Parser finished before end of input at /perl5/lib/perl5/YAML/Parser.pm line 4056, <> line 1.

perl-tiny-json

 invalid_correct
YAML::Tiny failed to find multi-line scalar content at /yaml/bin/perl-tiny-json line 12.

perl-tiny-perl

 invalid_correct
YAML::Tiny failed to find multi-line scalar content at /yaml/bin/perl-tiny-perl line 15.

perl-xs-json

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

    found an indentation indicator equal to 0

was found at document: 1, line: 1, column: 6
while scanning a block scalar at line: 1, column: 5

perl-xs-perl

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

    found an indentation indicator equal to 0

was found at document: 1, line: 1, column: 6
while scanning a block scalar at line: 1, column: 5

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/python3.12/site-packages/yaml/__init__.py", line 75, in parse
    while loader.check_event():
          ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 209, in parse_document_content
    if self.check_token(DirectiveToken,
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 239, in fetch_more_tokens
    return self.fetch_literal()
           ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 635, in fetch_literal
    self.fetch_block_scalar(style='|')
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 649, in fetch_block_scalar
    self.tokens.append(self.scan_block_scalar(style))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 989, in scan_block_scalar
    chomping, increment = self.scan_block_scalar_indicators(start_mark)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 1074, in scan_block_scalar_indicators
    raise ScannerError("while scanning a block scalar", start_mark,
yaml.scanner.ScannerError: while scanning a block scalar
  in "<unicode string>", line 1, column 5:
    --- |0
        ^
expected indentation indicator in the range 1-9, but found 0
  in "<unicode string>", line 1, column 6:
    --- |0
         ^
+STR
+DOC ---

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/python3.12/site-packages/yaml/__init__.py", line 130, in load_all
    yield loader.get_data()
          ^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/constructor.py", line 45, in get_data
    return self.construct_document(self.get_node())
                                   ^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 27, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 64, in compose_node
    if self.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 209, in parse_document_content
    if self.check_token(DirectiveToken,
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 239, in fetch_more_tokens
    return self.fetch_literal()
           ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 635, in fetch_literal
    self.fetch_block_scalar(style='|')
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 649, in fetch_block_scalar
    self.tokens.append(self.scan_block_scalar(style))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 989, in scan_block_scalar
    chomping, increment = self.scan_block_scalar_indicators(start_mark)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 1074, in scan_block_scalar_indicators
    raise ScannerError("while scanning a block scalar", start_mark,
yaml.scanner.ScannerError: while scanning a block scalar
  in "<unicode string>", line 1, column 5:
    --- |0
        ^
expected indentation indicator in the range 1-9, but found 0
  in "<unicode string>", line 1, column 6:
    --- |0
         ^

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/python3.12/site-packages/yaml/__init__.py", line 130, in load_all
    yield loader.get_data()
          ^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/constructor.py", line 45, in get_data
    return self.construct_document(self.get_node())
                                   ^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 27, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/composer.py", line 64, in compose_node
    if self.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/parser.py", line 209, in parse_document_content
    if self.check_token(DirectiveToken,
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 239, in fetch_more_tokens
    return self.fetch_literal()
           ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 635, in fetch_literal
    self.fetch_block_scalar(style='|')
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 649, in fetch_block_scalar
    self.tokens.append(self.scan_block_scalar(style))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 989, in scan_block_scalar
    chomping, increment = self.scan_block_scalar_indicators(start_mark)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/yaml/scanner.py", line 1074, in scan_block_scalar_indicators
    raise ScannerError("while scanning a block scalar", start_mark,
yaml.scanner.ScannerError: while scanning a block scalar
  in "<unicode string>", line 1, column 5:
    --- |0
        ^
expected indentation indicator in the range 1-9, but found 0
  in "<unicode string>", line 1, column 6:
    --- |0
         ^

py-ruamel-event

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-event", line 9, in <module>
    for event in yaml.parse(sys.stdin.read()):
  File "/python/lib/python3.12/site-packages/ruamel/yaml/main.py", line 371, in parse
    while parser.check_event():
          ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 141, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 279, in parse_document_content
    if self.scanner.check_token(
       ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 294, in fetch_more_tokens
    return self.fetch_literal()
           ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 680, in fetch_literal
    self.fetch_block_scalar(style='|')
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 691, in fetch_block_scalar
    self.tokens.append(self.scan_block_scalar(style))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 1112, in scan_block_scalar
    chomping, increment = self.scan_block_scalar_indicators(start_mark)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 1248, in scan_block_scalar_indicators
    raise ScannerError(
ruamel.yaml.scanner.ScannerError: while scanning a block scalar
  in "<unicode string>", line 1, column 5:
    --- |0
        ^ (line: 1)
expected indentation indicator in the range 1-9, but found 0
  in "<unicode string>", line 1, column 6:
    --- |0
         ^ (line: 1)
+STR
+DOC ---

py-ruamel-json

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-json", line 21, in <module>
    for doc in yaml.load_all(sys.stdin.read()):
  File "/python/lib/python3.12/site-packages/ruamel/yaml/main.py", line 476, in load_all
    yield constructor.get_data()
          ^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/constructor.py", line 110, in get_data
    return self.construct_document(self.composer.get_node())
                                   ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 63, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 94, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 106, in compose_node
    if self.parser.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 141, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 279, in parse_document_content
    if self.scanner.check_token(
       ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 294, in fetch_more_tokens
    return self.fetch_literal()
           ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 680, in fetch_literal
    self.fetch_block_scalar(style='|')
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 691, in fetch_block_scalar
    self.tokens.append(self.scan_block_scalar(style))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 1112, in scan_block_scalar
    chomping, increment = self.scan_block_scalar_indicators(start_mark)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 1248, in scan_block_scalar_indicators
    raise ScannerError(
ruamel.yaml.scanner.ScannerError: while scanning a block scalar
  in "<unicode string>", line 1, column 5:
    --- |0
        ^ (line: 1)
expected indentation indicator in the range 1-9, but found 0
  in "<unicode string>", line 1, column 6:
    --- |0
         ^ (line: 1)

py-ruamel-py

 invalid_correct
Traceback (most recent call last):
  File "/yaml/bin/py-ruamel-py", line 38, in <module>
    for doc in yaml.load_all(sys.stdin.read()):
  File "/python/lib/python3.12/site-packages/ruamel/yaml/main.py", line 476, in load_all
    yield constructor.get_data()
          ^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/constructor.py", line 110, in get_data
    return self.construct_document(self.composer.get_node())
                                   ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 63, in get_node
    return self.compose_document()
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 94, in compose_document
    node = self.compose_node(None, None)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/composer.py", line 106, in compose_node
    if self.parser.check_event(AliasEvent):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 141, in check_event
    self.current_event = self.state()
                         ^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/parser.py", line 279, in parse_document_content
    if self.scanner.check_token(
       ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 170, in check_token
    self.fetch_more_tokens()
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 294, in fetch_more_tokens
    return self.fetch_literal()
           ^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 680, in fetch_literal
    self.fetch_block_scalar(style='|')
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 691, in fetch_block_scalar
    self.tokens.append(self.scan_block_scalar(style))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 1112, in scan_block_scalar
    chomping, increment = self.scan_block_scalar_indicators(start_mark)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/python/lib/python3.12/site-packages/ruamel/yaml/scanner.py", line 1248, in scan_block_scalar_indicators
    raise ScannerError(
ruamel.yaml.scanner.ScannerError: while scanning a block scalar
  in "<unicode string>", line 1, column 5:
    --- |0
        ^ (line: 1)
expected indentation indicator in the range 1-9, but found 0
  in "<unicode string>", line 1, column 6:
    --- |0
         ^ (line: 1)

ruby-psych-json

 invalid_correct
/ruby/gems/psych/lib/psych.rb:458:in `parse': (<unknown>): found an indentation indicator equal to 0 while scanning a block scalar at line 1 column 5 (Psych::SyntaxError)
	from /ruby/gems/psych/lib/psych.rb:458:in `parse_stream'
	from /ruby/gems/psych/lib/psych.rb:632:in `load_stream'
	from /yaml/bin/ruby-psych-json:6:in `<main>'

rust-yamlrust-event

 invalid_correct
Error: ScanError { mark: Marker { index: 4, line: 1, col: 4 }, info: "while scanning a block scalar, found an indentation indicator equal to 0" }
+STR
+DOC