Handle obsolete runners more safely.

Resolves #4863

In case one winds up in the sidebar, it will have no actions.

lutris/gui/widgets/sidebar.py

@@ -15,6 +15,7 @@ from lutris.gui.dialogs import ErrorDialog
 from lutris.gui.dialogs.runner_install import RunnerInstallDialog
 from lutris.gui.widgets.utils import has_stock_icon
 from lutris.installer.interpreter import ScriptInterpreter
+from lutris.runners import InvalidRunner
 from lutris.services import SERVICES
 from lutris.services.base import AuthTokenExpired, BaseService
 
@@ -212,7 +213,11 @@ class RunnerSidebarRow(SidebarRow):
 
         # Creation is delayed because only installed runners can be imported
         # and all visible boxes should be installed.
-        self.runner = runners.import_runner(self.id)()
+        try:
+            self.runner = runners.import_runner(self.id)()
+        except InvalidRunner:
+            return entries
+
         if self.runner.multiple_versions:
             entries.append((
                 "system-software-install-symbolic",

lutris/runners/__init__.py

@@ -120,7 +120,10 @@ def get_runner_human_name(runner_name):
     names."""
     if runner_name:
         if runner_name not in _cached_runner_human_names:
-            _cached_runner_human_names[runner_name] = import_runner(runner_name)().human_name
+            try:
+                _cached_runner_human_names[runner_name] = import_runner(runner_name)().human_name
+            except InvalidRunner:
+                _cached_runner_human_names[runner_name] = runner_name  # an obsolete runner
         return _cached_runner_human_names[runner_name]
 
     return ""