Our testing page already had some debugging content so I’ve made the debugging page link to that ([lldb][Docs] Link to testing page from debugging page · llvm/llvm-project@3ae76e4 · GitHub).
We have some places you can’t use Pdb (AttributeError when using Pdb in lldb's script interpreter · Issue #66356 · llvm/llvm-project · GitHub) still.
Using Pdb is basically all I do to debug Python so if others have ideas please add them to the testing page, and to the debugging page for anything else.