watchpoints VS grub2-theme-preview

It's sad that Python does not really support some of these debugging methods.

E.g. you cannot really watch variable changes. There are some workarounds, like writing a custom __setattr__ or __setattribute__ in case of an object, or checking all STORE_* operations. https://youtrack.jetbrains.com/issue/PY-30387 https://github.com/gaogaotiantian/watchpoints

Reverse debugging is also sth I would like to have, and there are a few projects to support this, but it's not really well supported in standard CPython. https://foss.heptapod.net/pypy/revdb https://pytrace.com/

There is also the watchpoints module to track changes to variables, but I don't think you can use the two of them together since they both use the same underlying callback in Python.

It uses Python's built-in inspect module to get the caller frame. https://github.com/gaogaotiantian/watchpoints/blob/68bc13716...

It then uses sys.settrace (which is intended as an interface for debuggers) to step through the code and check whether the variable has been changed. Documentation on sys.settrace: https://docs.python.org/3/library/sys.html#sys.settrace

Python exposes most of its guts as part of the standard library, making clever hacks like this possible.

For grub theming, I used this (and then added some customisation of my own). And I used this to preview it.