Debugging docs for rust-gdb

[cjermain]

Since PyO3 uses cdylib for Python shared objects, it does not receive the pretty-print debug hooks in rust-gdb (rust-lang/rust#96365). I think adding information about this to the debugging documentation for PyO3 would help avoid confusion as to why pretty printers are not loaded. I'm happy to update the docs when I get a chance.
​https://github.com/PyO3/pyo3/blob/main/guide/src/debugging.md#L38

[davidhewitt]

Thanks for sharing! It sounds like this is potentially something that upstream rustc might fix one day?

[cjermain]

That is my hope. I'm not sure the right way to get visibility on the upstream issue.