Tired of patching around __version__ ...

This doesn't work. Either Python is too old, import_metadata
isn't there or Azure pipelines do not support that.
Stopping that. Good old plain C++ is still the best solution.
Take that dynamic language hackers!

setup.py

@@ -542,10 +542,12 @@ config.add_extension(_gsi)
 _pya_path = os.path.join("src", "pya", "pya")
 _pya_sources = set(glob.glob(os.path.join(_pya_path, "*.cc")))
 
+_version_path = os.path.join("src", "version")
+
 _pya = Library(
     config.root + "._pya",
-    define_macros=config.macros() + [("MAKE_PYA_LIBRARY", 1)],
-    include_dirs=[_tl_path, _gsi_path],
+    define_macros=config.macros() + [("MAKE_PYA_LIBRARY", 1), ("KLAYOUT_VERSION", config.version())],
+    include_dirs=[_version_path, _tl_path, _gsi_path],
     extra_objects=[config.path_of("_tl", _tl_path), config.path_of("_gsi", _gsi_path)],
     language="c++",
     libraries=config.libraries('_pya'),
@@ -974,9 +976,6 @@ if __name__ == "__main__":
         package_data={config.root: ["src/pymod/distutils_src/klayout/*.pyi"]},
         data_files=[(config.root, ["src/pymod/distutils_src/klayout/py.typed"])],
         include_package_data=True,
-        install_requires = [
-            'importlib-metadata <= 4.8.3 ; python_version < "3.8"',
-        ],
         ext_modules=[_tl, _gsi, _pya, _rba, _db, _lib, _rdb, _lym, _laybasic, _layview, _ant, _edt, _img]
             + db_plugins
             + [tl, db, lib, rdb, lay],

src/pya/pya/pyaModule.cc

@@ -34,6 +34,8 @@
 #include "pyaInternal.h"
 #include "pyaCallables.h"
 
+#include "version.h"
+
 #include <map>
 
 namespace pya
@@ -148,7 +150,7 @@ PythonModule::init (const char *mod_name, const char *description)
   memcpy ((void *) mp_mod_def, (const void *) &mod_def, sizeof (PyModuleDef));
 
   module = PyModule_Create ((PyModuleDef *) mp_mod_def);
-
+  
 #endif
 
   mp_module = PythonRef (module);
@@ -663,7 +665,13 @@ PythonModule::make_classes (const char *mod_name)
     all_list = PythonRef (PyObject_GetAttrString (module, "__all__"));
   }
 
+  //  Establish __doc__
   PyObject_SetAttrString (module, "__doc__", PythonRef (c2python (m_mod_description)).get ());
+  PyList_Append (all_list.get (), PythonRef (c2python ("__doc__")).get ());
+
+  //  Establish __version__
+  PyObject_SetAttrString (module, "__version__", PythonRef (c2python (prg_version)).get ());
+  PyList_Append (all_list.get (), PythonRef (c2python ("__version__")).get ());
 
   //  Build a class for descriptors for static attributes
   PYAStaticAttributeDescriptorObject::make_class (module);

src/pymod/distutils_src/klayout/__init__.py

@@ -1,10 +1,3 @@
-import sys
-if sys.version_info >= (3, 8):
-    from importlib import metadata
-else:
-    import importlib_metadata as metadata
 
-try:
-    __version__ = metadata.version('klayout')
-except Exception:
-    __version__ = 'unknown'
+from .tl import __version__
+