Failed to load CycloneDDS library from C:\bin\ddsc.dll

[avelin0]

Hello, I'm getting this error when trying to import cyclonedds-nightly. I have tried different versions of cyclonedds-nightly, but I'm getting the same error message. This here using cyclonedds-nightly 2024.10.12 and python 3.11.9 with Windows 11 appear "Failed to load CycloneDDS library from C:\bin\ddsc.dll" but this lib is there.

Traceback (most recent call last):
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\.venv\Lib\site-packages\cyclonedds\internal.py", line 34, in _load
    library = ct.CDLL(path)
              ^^^^^^^^^^^^^
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.11_3.11.2544.0_x64__qbz5n2kfra8p0\Lib\ctypes\__init__.py", line 376, in __init__
    self._handle = _dlopen(self._name, mode)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: Could not find module 'C:\bin\ddsc.dll' (or one of its dependencies). Try using the full path with constructor syntax.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\main.py", line 1, in <module>
    from cyclonedds import *
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\.venv\Lib\site-packages\cyclonedds\__init__.py", line 13, in <module>
    from . import internal, util, qos, core, domain, topic, pub, sub, builtin, dynamic, idl
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\.venv\Lib\site-packages\cyclonedds\internal.py", line 233, in <module>
    class DDS:
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\.venv\Lib\site-packages\cyclonedds\internal.py", line 237, in DDS
    _dll_handle = load_cyclonedds()
                  ^^^^^^^^^^^^^^^^^
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\.venv\Lib\site-packages\cyclonedds\internal.py", line 132, in load_cyclonedds
    lib = loader()
          ^^^^^^^^
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\.venv\Lib\site-packages\cyclonedds\internal.py", line 58, in _loader_cyclonedds_home
    return _load(os.path.join(os.environ["CYCLONEDDS_HOME"], name))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\avelino.bruno\PycharmProjects\proj-cyclonedds\.venv\Lib\site-packages\cyclonedds\internal.py", line 36, in _load
    raise CycloneDDSLoaderException(f"Failed to load CycloneDDS library from {path}")
cyclonedds.internal.CycloneDDSLoaderException: Failed to load CycloneDDS library from C:\bin\ddsc.dll

[noxpardalis]

I also ran into something similar. I think I've narrowed it down to some oddness in https://docs.python.org/3/library/ctypes.html#ctypes.CDLL on Windows. If

cyclonedds-python/cyclonedds/internal.py

Line 35 in da68496

library = ct.CDLL(path)

is changed to the following then it seems to work.

 library = ct.CDLL(path, winmode=0x2000) 

In fact I've tried a variety of values [0x0000, 0x0001, 0x2000] and they all seem to work as long as it's not the default of None. This parameter gets passed to LoadLibraryEx and you can find the table here: https://learn.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexa. I'm not 100% sure what the right value for it should be for Windows.