如果我单击“软件和更新”，它根本不会执行任何操作。
当我尝试从命令行运行它（无论是否使用 root 权限）时，它显示此错误：
$ sudo software-properties-gtk
ERROR:dbus.proxies:Introspect error on :1.162:/: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
Traceback (most recent call last):
File "/usr/bin/software-properties-gtk", line 100, in <module>
app = SoftwarePropertiesGtk(datadir=options.data_dir, options=options, file=file)
File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 211, in __init__
self.backend.Reload();
File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 72, in __call__
return self._proxy_method(*args, **keywords)
File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 141, in __call__
return self._connection.call_blocking(self._named_service,
File "/usr/lib/python3/dist-packages/dbus/connection.py", line 652, in call_blocking
reply_message = self.send_message_with_reply_and_block(
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name :1.162 was not provided by any .service files
我在 ASUS X550za 上运行 Ubuntu 20.04.1。有什么想法吗？
apt list software-properties-gtk -a根据建议，的输出：
Listing... Done
software-properties-gtk/focal-updates,focal-updates,now 0.98.9.3 all [installed,automatic]
software-properties-gtk/focal-security,focal-security 0.98.9.2 all
software-properties-gtk/focal,focal 0.98.9 all
我刚刚尝试在我的计算机上运行 nutty，但是收到了类似的错误消息：
$ nutty
[_LOG_LEVEL_INFO 18:41:28.656400] Application.vala:153: Nutty version: 0.9
[_LOG_LEVEL_INFO 18:41:28.656474] Application.vala:155: Kernel version: 5.4.0-54-generic
Failed to register: GDBus.Error:org.freedesktop.DBus.Error.AccessDenied: Connection ":1.114" is not allowed to own the service "org.nutty" due to AppArmor policy
这有关系吗？没有关系。
答案1
这是一个已知的错误（https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/1900098) 以获取来自 Ubuntu 的一些更新。解决方案很简单：
sudo apt reinstall python3-six python3-certifi