Fix handling of wrap-ignore for base classes to avoid invalid cimport in derived classes

Previously, autowrap would generate a `from ... cimport` statement for derived classes even if their base class was marked with `wrap-ignore`. This caused build failures due to missing .pxd files for ignored base classes, especially when those were the only contents of their file.

This change checks whether the base class has the `wrap-ignore` annotation and, if so, suppresses the cimport generation for the derived class. This prevents erroneous imports like:

  From ._pyopenms_20 cimport SpectrumAccessTransforming

When SpectrumAccessTransforming is intentionally not wrapped.

Also adds an optional debug message to clarify when this skip occurs.

This fix preserves expected behaviour for abstract base classes and improves compatibility when selectively wrapping a class hierarchy.

Fixes: #194

Author: codedbyasim

autowrap/CodeGenerator.py

@@ -1951,7 +1951,15 @@ def create_foreign_cimports(self):
                     if resolved.__class__ in (ResolvedClass,):
                         # Skip classes that explicitely should not have a pxd
                         # import statement (abstract base classes and the like)
-                        if not resolved.no_pxd_import:
+                        ignore_base = False
+                        # Check if this class has a base class and that base class is wrap-ignored
+                        if resolved.cpp_decl.parent:
+                            base_class = resolved.cpp_decl.parent
+                            if base_class.annotations.get("wrap-ignore"):
+                                ignore_base = True
+                                print(f"[autowrap] Skipping pxd import for derived class '{resolved.name}' "
+                                f"because base '{base_class.name}' is wrap-ignored.")
+                        if not resolved.no_pxd_import and not ignore_base:
                             if resolved.cpp_decl.annotations.get("wrap-attach"):
                                 code.add("from $mname cimport __$name", locals())
                             else: