Investigated the XFCE tray issue and confirmed the code path depends on build-time AppIndicator availability: GTK3 uses AppIndicator/StatusNotifier only when Ayatana/AppIndicator headers/libs were present at compile time; otherwise it falls back to GtkStatusIcon behavior. That fallback is less reliable across XFCE setups, which explains why one user could miss the tray icon.

Added a new Meson feature option appindicator (default auto) so this backend is explicitly controllable.

    Updated GTK Meson logic to honor -Dappindicator=... and fail fast if enabled is requested but neither ayatana-appindicator3-0.1 nor appindicator3-0.1 is found (prevents silently shipping a build without AppIndicator tray support).

    Updated AppImage CI configure flags to force -Dappindicator=enabled, which should prevent AppImage artifacts from lacking StatusNotifier/AppIndicator tray support in XFCE-like environments.

.github/workflows/appimage-build.yml

@@ -47,7 +47,8 @@ jobs:
             -Dtext-frontend=true \
             -Dwith-perl=perl \
             -Dwith-python=python3 \
-            -Dauto_features=enabled
+            -Dauto_features=enabled \
+            -Dappindicator=enabled
 
       - name: Build
         run: |

meson_options.txt

@@ -22,6 +22,9 @@ option('dbus', type: 'feature', value: 'auto',
 option('libcanberra', type: 'feature', value: 'auto',
   description: 'Support for sound alerts, Unix only'
 )
+option('appindicator', type: 'feature', value: 'auto',
+  description: 'Use Ayatana/AppIndicator-based tray backend when GTK3 is enabled'
+)
 
 # Install options
 option('dbus-service-use-appid', type: 'boolean', value: false,

src/fe-gtk/meson.build

@@ -40,15 +40,21 @@ if get_option('gtk3')
   zoitechat_gtk_cflags += '-DHAVE_GTK3'
 
   if host_machine.system() != 'windows'
-    appindicator_dep = dependency('ayatana-appindicator3-0.1', required: false)
+    appindicator_opt = get_option('appindicator')
-    if appindicator_dep.found()
+
-      zoitechat_gtk_deps += appindicator_dep
+    if appindicator_opt.allowed()
-      zoitechat_gtk_cflags += '-DHAVE_AYATANA_APPINDICATOR'
+      appindicator_dep = dependency('ayatana-appindicator3-0.1', required: false)
-    else
-      appindicator_dep = dependency('appindicator3-0.1', required: false)
       if appindicator_dep.found()
         zoitechat_gtk_deps += appindicator_dep
-        zoitechat_gtk_cflags += '-DHAVE_APPINDICATOR'
+        zoitechat_gtk_cflags += '-DHAVE_AYATANA_APPINDICATOR'
+      else
+        appindicator_dep = dependency('appindicator3-0.1', required: false)
+        if appindicator_dep.found()
+          zoitechat_gtk_deps += appindicator_dep
+          zoitechat_gtk_cflags += '-DHAVE_APPINDICATOR'
+        elif appindicator_opt.enabled()
+          error('appindicator=enabled, but neither ayatana-appindicator3-0.1 nor appindicator3-0.1 was found')
+        endif
       endif
     endif
   endif