core&ui: add addon not found warning

packages/hydrooj/src/loader.ts

@@ -16,6 +16,8 @@ import { Logger } from './logger';
 import { Context } from './context';
 // eslint-disable-next-line import/no-duplicates
 import { unwrapExports } from './utils';
+import { PRIV } from './model/builtin';
+import { inject } from './lib/ui';
 
 const argv = cac().parse();
 const logger = new Logger('loader');
@@ -95,6 +97,7 @@ export function addon(addonPath: string, prepend = false) {
     } catch (e) {
         logger.error(`Addon not found: ${addonPath}`);
         logger.error(e);
+        inject('Notification', 'Addon not found: {0}', { args: [addonPath] }, PRIV.PRIV_VIEW_SYSTEM_NOTIFICATION);
     }
 }