Handle 'stub' modules that don't have a __spec__ (#328)

Author: peterebden

tools/please_pex/ChangeLog

@@ -1,3 +1,7 @@
+Version 3.0.4
+-------------
+    * Handle 'stub' modules that don't have a __spec__
+
 Version 3.0.3
 -------------
     * Fix `importlib.resources` for some usages relating to packages in module_dir (#324)

tools/please_pex/VERSION

@@ -1 +1 @@
-3.0.3
+3.0.4

tools/please_pex/pex/plz.py

@@ -154,9 +154,10 @@ def create_module(self, spec):
         # Carry over submodule_search_locations from the real module's spec, otherwise
         # importlib.resources (which relies on it to find a package's files) breaks once
         # the module's __spec__ gets overwritten with this one.
-        real_spec = module.__spec__
-        spec.submodule_search_locations = real_spec.submodule_search_locations
-        self._real_specs[spec.name] = real_spec
+        real_spec = getattr(module, "__spec__", None)
+        if real_spec is not None:
+            spec.submodule_search_locations = real_spec.submodule_search_locations
+            self._real_specs[spec.name] = real_spec
         sys.modules[spec.name] = module
         return module