fix: Systray icon consider restricted privileges of scheduled root-mode or foreign-user backup profiles

CHANGES

@@ -59,6 +59,7 @@ Version 1.6.0-dev (development of upcoming release)
 * Fixed: Stop waking up monitor when inhibit suspend on backup starts (#714, #1090)
 * Fixed: Avoid shutdown confirmation dialog on Budgie and Cinnamon desktop environments (#788)
 * Fixed: Crash in "Manage profiles" dialog when using "qt6ct" (#2128)
+* Fixed: **Breaking** Systray icon consider restricted privileges of scheduled root-mode or foreign-user backup profiles (#2237, reported and co-contributed by @samo-sk)
 * Fixed: Allow in BITs root-mode opening URLs in extern browse
 
 Version 1.5.6 (2025-10-05)

qt/plugins/systrayiconplugin.py

@@ -107,6 +107,9 @@ def processBegin(self):  # noqa: N802
         except Exception as exc:
             logger.critical(f'Undefined situation: {exc}', self)
 
+        else:
+            logger.info('Systray icon sub process started.')
+
     # def processEnd(self):
     #     """Dev note(2025-07, buhtz): Method makes no sense to me anymore.
     #     Remove it soon.

qt/qtsystrayicon.py

@@ -13,6 +13,8 @@
 """Separate application managing the systray icon"""
 import sys
 import os
+import re
+import json
 import subprocess
 import signal
 import textwrap
@@ -69,9 +71,12 @@ def __init__(self):
         self.status_icon = self._create_status_icon()
         self.contextMenu = QMenu()
 
+        desktop_user = self._determine_desktop_session_user()
+
         self.menuProfileName = self.contextMenu.addAction(
-            _('Profile: {profile_name}').format(
-                profile_name=self.config.profileName())
+            _('Profile: {profile_name} USER: {desktop_user}').format(
+                profile_name=self.config.profileName(),
+                desktop_user=desktop_user)
         )
         self.contextMenu.addSeparator()
 
@@ -285,6 +290,146 @@ def onBtnStop(self):
         self.btnResume.setEnabled(False)
         self.snapshots.setTakeSnapshotMessage(0, 'Backup terminated')
 
+    def _get_desktop_user_via_loginctl(self) -> str | None:
+        """Get name of user logged in to the current desktop session using
+        loginctl.
+        """
+
+        try:
+            # get list of sessions
+            output = subprocess.check_output(
+                ['loginctl', 'list-sessions', '--no-legend', '--json=short'],
+                text=True)
+
+        except FileNotFoundError:
+            logger.warning(
+                'Can not determine user name of current desktop '
+                'session because "loginctl" is not available.'
+            )
+            return None
+
+        except Exception as exc:
+            logger.error(
+                'Unexpected error while determining user name of '
+                f'current desktop session: {exc}'
+            )
+            return None
+
+        sessions = []
+
+        # Check each session
+        for session in json.loads(output):
+            # Ignore none-user sessions
+            if session.get('class') != 'user':
+                continue
+
+            # properties of the session
+            info = subprocess.check_output(
+                [
+                    'loginctl',
+                    'show-session',
+                    str(session['session']),
+                    '--property=Active',
+                    '--property=Name',
+                    '--property=Seat',
+                    '--property=Type',
+                    '--property=Dispplay',
+                ],
+                text=True
+            ).strip()
+
+            props = dict(line.split('=', 1) for line in info.splitlines())
+            sessions.append(props)
+
+        display = os.environ.get('DISPLAY')
+
+        if display:
+            display = display.split('.')[0]
+
+            matches = [
+                s for s in sessions
+                if s.get('Display', '').split('.')[0] == display
+            ]
+
+            if len(matches) == 1:
+                logger.info(
+                    f'VARIANT - systemd loginctl DISPLAY: {matches[0]=}',
+                    self,
+                )
+                return matches[0].get('Name')
+
+            return None
+
+        # Fallback checking for one active session, if DISPLAY not set
+        fallback = [
+            s for s in sessions
+            if s.get('Active', '').lower() == 'yes'
+            and s.get('Seat') == 'seat0'
+            and s.get('Type') in ('x11', 'wayland')
+        ]
+
+        if len(fallback) == 1:
+            logger.info(
+                f'VARIANT - systemd loginctl SAFE FALLBACK: {fallback[0]=}',
+                self,
+            )
+            return fallback[0].get('Name')
+
+        return None
+
+    def _get_desktop_user_via_x11_who(self) -> str | None:
+        """Using 'who' to determine the current DISPLAY's user.
+
+        The output of 'who' can look like this:
+
+        user     sshd pts/0   2025-09-16 08:30 (fe80::d65:ea81:c46f:7f0d%eth0)
+        lightdm  seat0        2025-09-15 16:07 (:0)
+        """
+        if not os.environ.get('DISPLAY'):
+            return None
+
+        try:
+            # list of users logged in
+            output = subprocess.check_output(['who'], text=True).strip()
+        except Exception as exc:
+            logger.error(
+                'Unexpected error while determining user name of '
+                f'current desktop session: {exc}'
+            )
+            return None
+
+        display = os.environ.get('DISPLAY', ':0').split('.')[0]
+
+        # each user
+        for line in output:
+            found = re.match(r'^(\S+).*\((.*)\)$', line)
+
+            if not found:
+                continue
+
+            user, userdisplay = found.groups()
+            userdisplay = userdisplay.split('.')[0]
+
+            if userdisplay == display:
+                logger.info(f'VARIANT - X11 who DISPLAY: {user=}', self)
+                return user
+
+        return None
+
+    def _determine_desktop_session_user(self):
+        """Return name of user logged in to the current desktop session.
+        """
+        user = self._get_desktop_user_via_loginctl()
+
+        if not user:
+            user = self._get_desktop_user_via_x11_who()
+
+        logger.info(
+            f'Systray Icon determined user "{user}" as owner of '
+            'current desktop session.')
+
+        return user
+
     @classmethod
     def _get_icon_filled(cls, color: str) -> QIcon:
         """Generate the dark symbolic icon"""
@@ -311,7 +456,8 @@ def get_light_icon() -> QIcon:
     if '--debug' in sys.argv:
         logger.DEBUG = True
 
-    logger.debug('Sub process tries to show systray icon, '
-                 f'called with args {str(sys.argv)}')
+    logger.debug(
+        f'Systray icon process (PID: {os.getpid()} User: {logger.USER}) '
+        f'called with {sys.argv}')
 
     QtSysTrayIcon().run()