only appimage supports autoupdates on linux

src/main/updater.main.ts

@@ -2,11 +2,15 @@ import {
     dialog,
     Menu,
     MenuItem,
+    shell,
 } from 'electron';
 import { autoUpdater } from 'electron-updater';
 
 import { Main } from '../main';
-import { isDev } from '../scripts/utils';
+import {
+    isDev,
+    isAppImage,
+} from '../scripts/utils';
 
 const UpdaterCheckInitalDelay = 5 * 1000; // 5 seconds
 const UpdaterCheckInterval = 12 * 60 * 60 * 1000; // 12 hours
@@ -103,6 +107,14 @@ export class UpdaterMain {
             return;
         }
 
+        if (process.platform === 'linux' && !isAppImage()) {
+            if (withFeedback) {
+                shell.openExternal('https://github.com/bitwarden/desktop/releases');
+            }
+
+            return;
+        }
+
         this.doingUpdateCheckWithFeedback = withFeedback;
         if (withFeedback) {
             autoUpdater.autoDownload = false;

src/scripts/utils.ts

@@ -5,3 +5,7 @@ export function isDev() {
     }
     return (process.defaultApp || /node_modules[\\/]electron[\\/]/.test(process.execPath));
 }
+
+export function isAppImage() {
+    return 'APPIMAGE' in process.env;
+}