Python debugging is great when you're strictly debugging Python code. Placing a `breakpoint` or spinning up an IPython instance to investigate the issue via `import IPython; IPython.embed()` makes life breezy. For neovim, you can send code to the ipython REPL easily via vim-slime.

I've never found myself debugging the underlying C++ code unless developing a C++ extension. But is it really that hard? Just point lldb to the python process and run your script in lldb.

If the C++ is not yours & assuming it's a mature lib (e.g. PyTorch): it's probably an error caused by you in Python land.