track missing stub packages even when ignore_missing_imports is set

Author: knQzx

mypy/build.py

@@ -3414,6 +3414,12 @@ def find_module_and_diagnose(
         if caller_state:
             if not (ignore_missing_imports or in_partial_package(id, manager)):
                 module_not_found(manager, caller_line, caller_state, id, result)
+            elif result is ModuleNotFoundReason.APPROVED_STUBS_NOT_INSTALLED:
+                # Even when ignoring missing imports, track approved stub packages
+                # so that --install-types can still install them.
+                dist = stub_distribution_name(id)
+                if dist:
+                    manager.missing_stub_packages.add(dist)
             raise ModuleNotFound
         elif root_source:
             # If we can't find a root source it's always fatal.