pypdfium2 to uses custom fork of ctypesgen to generate ctypes bindings from shared libraries and headers, https://github.com/pypdfium2-team/ctypesgen . The ctypes bindings must be re-generated every time we update libpdfium to a new PDFium version. AFAIK newer pypdfium2 versions also need a more recent version of ctypesgen.

In the past, I ran ctypesgen in the libpdfium RPM build process and includes the ctypes bindings in the RPM. It would make more sense to move the step into a builder plugin. It's more flexible, too.