@@ -3214,11 +3214,17 @@ impl SetAttr for PyType {
             } else {
                 let prev_value = zelf.attributes().remove(attr_name);
                 if prev_value.is_none() {
-                    return Err(vm.new_attribute_error(format!(
+                    let exc = vm.new_attribute_error(format!(
                         "type object '{}' has no attribute '{}'",
                         zelf.name(),
                         attr_name,
-                    )));
+                    ));
+                    vm.set_attribute_error_context(
+                        &exc,
+                        zelf.to_owned().into(),
+                        attr_name.to_owned(),
+                    );
+                    return Err(exc);
                 }
                 prev_value
             };
 
@@ -1,5 +1,44 @@
 pub(crate) use _sysconfig::module_def;
 
+#[pymodule]
+pub(crate) mod _missing_stdlib_info {
+    use crate::{VirtualMachine, builtins::PyDictRef, convert::ToPyObject};
+
+    #[pyattr(name = "_MISSING_STDLIB_MODULE_MESSAGES")]
+    fn missing_stdlib_module_messages(vm: &VirtualMachine) -> PyDictRef {
+        let messages = vm.ctx.new_dict();
+        // CPython's Tools/build/check_extension_modules.py emits these entries
+        // unconditionally, including on Windows. Do not infer disabled build
+        // features from CPython's module inventory: ours is different.
+        for name in [
+            "_overlapped",
+            "_testconsole",
+            "_winapi",
+            "_wmi",
+            "msvcrt",
+            "nt",
+            "winreg",
+            "winsound",
+        ] {
+            let message =
+                format!("Unsupported platform for Windows-only standard library module '{name}'");
+            messages
+                .set_item(name, message.to_pyobject(vm), vm)
+                .unwrap();
+        }
+        // This module is only implemented for macOS in our stdlib as well.
+        #[cfg(not(target_os = "macos"))]
+        messages
+            .set_item(
+                "_scproxy",
+                "Unsupported platform for standard library module '_scproxy'".to_pyobject(vm),
+                vm,
+            )
+            .unwrap();
+        messages
+    }
+}
+
 #[pymodule]
 pub(crate) mod _sysconfig {
     use crate::{VirtualMachine, builtins::PyDictRef, convert::ToPyObject};
 
@@ -140,6 +140,7 @@ pub fn builtin_module_defs(ctx: &Context) -> Vec<&'static PyModuleDef> {
         _symtable::module_def(ctx),
         _sysconfigdata::module_def(ctx),
         _sysconfig::module_def(ctx),
+        _sysconfig::_missing_stdlib_info::module_def(ctx),
         #[cfg(feature = "threading")]
         _thread::module_def(ctx),
         _interpchannels::module_def(ctx),