disco: print the name of the plugin if it fails to load (#9719)

certbot/certbot/_internal/plugins/disco.py

@@ -189,8 +189,14 @@ def find_all(cls) -> 'PluginsRegistry':
             pkg_resources.iter_entry_points(
                 constants.OLD_SETUPTOOLS_PLUGINS_ENTRY_POINT),)
         for entry_point in entry_points:
-            cls._load_entry_point(entry_point, plugins)
-
+            try:
+                cls._load_entry_point(entry_point, plugins)
+            except Exception as e:
+                raise errors.PluginError(
+                    f"The '{entry_point.module_name}' plugin errored while loading: {e}. "
+                     "You may need to remove or update this plugin. The Certbot log will "
+                     "contain the full error details and this should be reported to the "
+                     "plugin developer.") from e
         return cls(plugins)
 
     @classmethod

certbot/certbot/_internal/tests/plugins/disco_test.py

@@ -194,6 +194,17 @@ def test_find_all(self):
         assert plugins["ep1"].entry_point is self.ep1
         assert "p1:ep1" not in plugins
 
+    def test_find_all_error_message(self):
+        from certbot._internal.plugins.disco import PluginsRegistry
+        with mock.patch("certbot._internal.plugins.disco.pkg_resources") as mock_pkg:
+            EP_SA.load = None # This triggers a TypeError when the entrypoint loads
+            mock_pkg.iter_entry_points.side_effect = [
+                iter([EP_SA]), iter([EP_WR, self.ep1])
+            ]
+            with self.assertRaises(errors.PluginError) as cm:
+                PluginsRegistry.find_all()
+            assert "standalone' plugin errored" in str(cm.exception)
+
     def test_getitem(self):
         assert self.plugin_ep == self.reg["mock"]