gh-138978: Fully qualified name for abc classes exception.

[skv0zsneg]

• Issue: Improve UX by using fully-qualified name in some TypeError #138978

[skv0zsneg]

After adding changes to tests and typeobjec.c the strange error appear

AssertionError: 'Cmd click to launch VS Code Native REPL\nok! Py_RunMain() returned 123' != 'ok! Py_RunMain() returned 123'
- Cmd click to launch VS Code Native REPL
  ok! Py_RunMain() returned 123

So, I changed it for checking exactly "ok!..." string.

[maurycy]

Could you check if it happens from CLI? My hunch is that it's VS Code artifact

[skv0zsneg]

Wow, yes. From CLI test is not falling.

I do not clearly understand what this test (and others in Lib/test/test_embed.py) checking. Integrations with IDE's?

[maurycy]

I suspect that the C part can be a bit smaller, using %N

cpython/Objects/unicodeobject.c

Lines 3019 to 3049 in aad4288

	case 'N':
	{
	PyObject *type_raw = va_arg(*vargs, PyObject *);
	assert(type_raw != NULL);
	if (!PyType_Check(type_raw)) {
	PyErr_SetString(PyExc_TypeError, "%N argument must be a type");
	return NULL;
	}
	PyTypeObject *type = (PyTypeObject*)type_raw;
	PyObject *type_name;
	if (flags & F_ALT) {
	type_name = _PyType_GetFullyQualifiedName(type, ':');
	}
	else {
	type_name = PyType_GetFullyQualifiedName(type);
	}
	if (!type_name) {
	return NULL;
	}
	if (unicode_fromformat_write_str(writer, type_name,
	width, precision, flags) == -1) {
	Py_DECREF(type_name);
	return NULL;
	}
	Py_DECREF(type_name);
	break;
	}
	default: