Import Errors with ruamel.yaml >= 0.16.0

[Tom Wolhuter]

Hi, I've been using PyInstaller to compile a program that uses the ruamel.yaml package (https://sourceforge.net/p/ruamel-yaml/code/ci/default/tree/). I was using PyInstaller 3.6 on Fedora 30 with Python 3.7 and version 0.15.41 of ruamel.yaml. Everything was working fine under these conditions, but when I tried to use anything >= 0.16.0 of ruamel.yaml my PyInstaller compiled program would throw an ImportError. I've since migrated to Fedora 32 and started using the latest dev version of PyInstaller and not only is the ruamel.yaml issue still present but I no longer have the option to use ruamel.yaml < 0.16.0. I know that with 0.16.0 the c source was split to a different package and I think that's what's causing the issue. After writing some test scripts (attached) I've discovered that the compiled script can import ruamel.yaml but can't properly import any of the submodules or execute the __init__ properly (which imports everything from ruamel.yaml.main as part of ruamel.yaml). I've attempted to write a hook (attached) to overcome this, which makes my test script run properly, but ruamel.yaml still isn't imported properly which is still causing problem with the original program. I can also see in the PYZ-00.pyz that all the submodules are there when using < 0.16.0 but not there when using >=0.16.0.

Output of my script using Python:

['AliasEvent', 'AliasToken', 'AnchorToken', 'BaseConstructor', 'BaseDumper', 'BaseLoader', 'BaseRepresenter', 'BlockEndToken', 'BlockEntryToken', 'BlockMappingStartToken', 'BlockSequenceStartToken', 'BytesIO', 'CBaseDumper', 'CBaseLoader', 'CDumper', 'CEmitter', 'CLoader', 'CParser', 'CSafeDumper', 'CSafeLoader', 'CollectionEndEvent', 'CollectionNode', 'CollectionStartEvent', 'CommentCheck', 'CommentToken', 'Constructor', 'DirectiveToken', 'DocumentEndEvent', 'DocumentEndToken', 'DocumentStartEvent', 'DocumentStartToken', 'Dumper', 'Event', 'FlowEntryToken', 'FlowMappingEndToken', 'FlowMappingStartToken', 'FlowSequenceEndToken', 'FlowSequenceStartToken', 'KeyToken', 'Loader', 'MappingEndEvent', 'MappingNode', 'MappingStartEvent', 'Node', 'NodeEvent', 'PY3', 'Representer', 'Resolver', 'RoundTripConstructor', 'RoundTripDumper', 'RoundTripLoader', 'RoundTripRepresenter', 'SHOWLINES', 'SafeConstructor', 'SafeDumper', 'SafeLoader', 'SafeRepresenter', 'ScalarEvent', 'ScalarNode', 'ScalarToken', 'SequenceEndEvent', 'SequenceNode', 'SequenceStartEvent', 'StreamEndEvent', 'StreamEndToken', 'StreamStartEvent', 'StreamStartToken', 'StringIO', 'TagToken', 'Token', 'UnsafeLoader', 'UnsafeLoaderWarning', 'ValueToken', 'VersionedResolver', 'YAML', 'YAMLContextManager', 'YAMLError', 'YAMLObject', 'YAMLObjectMetaclass', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__', '__version__', '__with_libyaml__', '_package_data', 'absolute_import', 'add_constructor', 'add_implicit_resolver', 'add_multi_constructor', 'add_multi_representer', 'add_path_resolver', 'add_representer', 'anchor', 'comments', 'compat', 'compose', 'compose_all', 'composer', 'constructor', 'cyaml', 'division', 'dump', 'dump_all', 'dumper', 'emit', 'emitter', 'enc', 'enforce', 'error', 'events', 'glob', 'import_module', 'load', 'load_all', 'loader', 'main', 'nodes', 'nprint', 'os', 'parse', 'parser', 'print_function', 'reader', 'representer', 'resolver', 'round_trip_dump', 'round_trip_load', 'round_trip_load_all', 'ruamel', 'safe_dump', 'safe_dump_all', 'safe_load', 'safe_load_all', 'scalarbool', 'scalarfloat', 'scalarint', 'scalarstring', 'scan', 'scanner', 'serialize', 'serialize_all', 'serializer', 'string_types', 'sys', 'timestamp', 'tokens', 'unicode_literals', 'util', 'version_info', 'warnings', 'with_metaclass', 'yaml_object']
['Xdump_all', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_indent', 'block_seq_indent', 'compact', 'composer', 'constructor', 'dump', 'dump_all', 'emitter', 'get_constructor_parser', 'get_serializer_representer_emitter', 'indent', 'load', 'load_all', 'map', 'official_plug_ins', 'parse', 'parser', 'reader', 'register_class', 'representer', 'resolver', 'scanner', 'seq', 'serializer']
['__cause__', '__class__', '__context__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__', '__str__', '__subclasshook__', '__suppress_context__', '__traceback__', '__weakref__', 'args', 'with_traceback']

Output of the PyInstaller compiled script:

['__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__', 'anchor', 'comments', 'compat', 'composer', 'constructor', 'dumper', 'emitter', 'error', 'events', 'loader', 'main', 'nodes', 'parser', 'reader', 'representer', 'resolver', 'scalarbool', 'scalarfloat', 'scalarint', 'scalarstring', 'scanner', 'serializer', 'timestamp', 'tokens', 'util']
['Xdump_all', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_indent', 'block_seq_indent', 'compact', 'composer', 'constructor', 'dump', 'dump_all', 'emitter', 'get_constructor_parser', 'get_serializer_representer_emitter', 'indent', 'load', 'load_all', 'map', 'official_plug_ins', 'parse', 'parser', 'reader', 'register_class', 'representer', 'resolver', 'scanner', 'seq', 'serializer']
['__cause__', '__class__', '__context__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__', '__str__', '__subclasshook__', '__suppress_context__', '__traceback__', '__weakref__', 'args', 'with_traceback']

If anyone has any ideas on a fix for this issue, or how to improve the hook, that would be greatly appreciated :)