pybind11 3.0.0 incompatibility

[Chriisbrown]

The most recent versions of pybind11 3.0.0+ break the cpp backend with the following error message:

This is solved by rolling back to pybind11 2.13.6

Either we try and fix this issue or add in the requirements the older version of pybind11, note that new python environments by default will install pybind11 3.0.0+

[thesps]

Thanks for flagging this. A bit more debugging from running the sklearn_to_cpp.py:

bridge.__dict__ for 3.0.0:

{'__name__': 'conifer_bridge_1754923943',
 '__doc__': None,
 '__package__': '',
 '__loader__': <_frozen_importlib_external.ExtensionFileLoader at 0x101294c10>,
 '__spec__': ModuleSpec(name='conifer_bridge_1754923943', loader=<_frozen_importlib_external.ExtensionFileLoader object at 0x101294c10>, origin='/path_to_workspace/conifer/examples/prj_cpp_1754923943/conifer_bridge_1754923943.so'),
 '__file__': '/path_to_workspace/conifer/examples/prj_cpp_1754923943/conifer_bridge_1754923943.so'}

bridge.__dict__ for 2.13.6:

{'__name__': 'conifer_bridge_1754924337',
 '__doc__': None,
 '__package__': '',
 '__loader__': <_frozen_importlib_external.ExtensionFileLoader at 0x104873610>,
 '__spec__': ModuleSpec(name='conifer_bridge_1754924337', loader=<_frozen_importlib_external.ExtensionFileLoader object at 0x104873610>, origin='/path_to_workspace/conifer/examples/prj_cpp_1754924337/conifer_bridge_1754924337.so'),
 'BDT': conifer_bridge_1754924337.BDT,
 '__file__': '/path_to_workspace/conifer/examples/prj_cpp_1754924337/conifer_bridge_1754924337.so'}

So that's just to confirm: the module seems to still compile fine, and load, but it does indeed lack the BDT instance that is there with 2.13.6