Currently the parser is intermixed with the code. It prevents it from being regenerated.

https://gitlab.com/kaitaiStructCompile.py/kaitaiStructCompile.py

In fact

• that stuff is alpha quality and I improve and refactor it quite often;
• some parts, like postprocessors will be heavily refactored in future;
• it has some security (not a very severe ones) and performance issues (there is a backend in which they have been resolved, but there is a legal issue in it called GNU GPL v3 because it calls directly into KSC)
• kaitaiStructCompile.setuptools has an issue that it is executed when setup is called, not when actual building is done. It is mainly a setuptools issue: setuptools doesn't have all the needed facilities to insert a stage;

..., but I still use it in all my project using Kaitai-generated parsers.

Feel free to fork and contribute.