网络指示器丢失但已连接（16.04 LTS Unity）

在最近一次升级之后，似乎我已经删除了network-manager-gnome，或者升级了-f了，所以在面板上看不到网络指示器。网络处于活动状态，包括无线和本地网络。

我努力了：

1. nm-applet，尚未安装。如果尝试通过安装network-manager-gnome进行安装，则会收到：

   The following packages have unmet dependencies: 
   network-manager-gnome : Depends: default-dbus-session-bus but it is not installable or dbus-session-bus but it is not installable
                           Recommends: mobile-broadband-provider-info but it is not going to be installed
   E: Unable to correct problems, you have held broken packages.
   

2. 重新启动服务sudo service network-manager restart只是重新启动它以使其再次运行，但是同样，没有指示器。

编辑（请求的输出）：

• 输出cat nm-applet：

  [Desktop Entry]
  Name=Network
  Comment=Manage your network connections
  Icon=nm-device-wireless
  Exec=nm-applet
  Terminal=false
  Type=Application
  NoDisplay=true
  NotShowIn=KDE;GNOME;
  X-GNOME-Bugzilla-Bugzilla=GNOME
  X-GNOME-Bugzilla-Product=NetworkManager
  X-GNOME-Bugzilla-Component=nm-applet
  X-GNOME-UsesNotifications=true
  X-Ubuntu-Gettext-Domain=nm-applet
  

• locate nm-applet 表示：

  gaj@gaj-Lenovo-Z51-70:~$ locate nm-applet
  /etc/xdg/autostart/nm-applet.desktop
  /usr/share/app-install/desktop/network-manager-gnome:nm-applet.desktop
  /usr/share/locale-langpack/en_AU/LC_MESSAGES/nm-applet.mo
  /usr/share/locale-langpack/en_CA/LC_MESSAGES/nm-applet.mo
  /usr/share/locale-langpack/en_GB/LC_MESSAGES/nm-applet.mo
  /usr/share/locale-langpack/hr/LC_MESSAGES/nm-applet.mo
  

• 如果我尝试使用aptitudei 来安装network-manager-gnome，请执行以下操作：

  The following NEW packages will be installed:
    network-manager-gnome{b} 
  0 packages upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
  Need to get 910 kB of archives. After unpacking 6049 kB will be used.
  The following packages have unmet dependencies:
   network-manager-gnome : Depends: default-dbus-session-bus which is a virtual package and is not provided by any available package.
   or
                                    dbus-session-bus which is a virtual package and is not provided by any available package.
  
  The following actions will resolve these dependencies:
  
       Keep the following packages at their current version:
  1)     network-manager-gnome [Not Installed]              
  
  
  
  Accept this solution? [Y/n/q/?] y
  

  输出：

  Starting pkgProblemResolver with broken count: 1
  Starting 2 pkgProblemResolver with broken count: 1
  Investigating (0) network-manager-gnome [ amd64 ] < none -> 1.2.4-0ubuntu2~ubuntu16.04.1~ppa1 > ( gnome )
  Broken network-manager-gnome:amd64 Depends on default-dbus-session-bus [ amd64 ] < none > ( none )
  Broken network-manager-gnome:amd64 Depends on dbus-session-bus [ amd64 ] < none > ( none )
  Done
  Some packages could not be installed. This may mean that you have
  requested an impossible situation or if you are using the unstable
  distribution that some required packages have not yet been created
  or been moved out of Incoming.
  The following information may help to resolve the situation:
  
  The following packages have unmet dependencies:
   network-manager-gnome : Depends: default-dbus-session-bus but it is not installable or
                                    dbus-session-bus but it is not installable
  E: Unable to correct problems, you have held broken packages.
  

您的locate命令表明您从usr/share/nm-applet/目录中丢失了大量内容。您可以在此处找到的network-manager-gnome_1.1.93-1ubuntu1_amd64.deb包中找到丢失的内容。如果您无法通过常规方式安装它，则dpkg对于这种情况和发出命令的影响很大sudo dpkg -i --force-downgrade network-manager-gnome_1.1.93-1ubuntu1_amd64.deb

如果您当前有备份， 则要使用更大的锤子，可以使用--force-depends或--force-all开关

我不是在开玩笑。以下命令提供了有关dpkg force选项的更多信息：dpkg --force-help为方便起见，我在下面复制了这些信息：

dpkg forcing options - control behaviour when problems found:
  warn but continue:  --force-<thing>,<thing>,...
  stop with error:    --refuse-<thing>,<thing>,... | --no-force-<thing>,...
 Forcing things:
  [!] all                Set all force options
  [*] downgrade          Replace a package with a lower version
      configure-any      Configure any package which may help this one
      hold               Process incidental packages even when on hold
      not-root           Try to (de)install things even when not root
      bad-path           PATH is missing important programs, problems likely
      bad-verify         Install a package even if it fails authenticity check
      bad-version        Process even packages with wrong versions
      overwrite          Overwrite a file from one package with another
      overwrite-diverted Overwrite a diverted file with an undiverted version
  [!] overwrite-dir      Overwrite one package's directory with another's file
  [!] unsafe-io          Do not perform safe I/O operations when unpacking
  [!] confnew            Always use the new config files, don't prompt
  [!] confold            Always use the old config files, don't prompt
  [!] confdef            Use the default option for new config files if one
                         is available, don't prompt. If no default can be found,
                         you will be prompted unless one of the confold or
                         confnew options is also given
  [!] confmiss           Always install missing config files
  [!] confask            Offer to replace config files with no new versions
  [!] architecture       Process even packages with wrong or no architecture
  [!] breaks             Install even if it would break another package
  [!] conflicts          Allow installation of conflicting packages
  [!] depends            Turn all dependency problems into warnings
  [!] depends-version    Turn dependency version problems into warnings
  [!] remove-reinstreq   Remove packages which require installation
  [!] remove-essential   Remove an essential package

WARNING - use of options marked [!] can seriously damage your installation.
Forcing options marked [*] are enabled by default.

看来您从ppa：vascofalves / gnome-backports获得了已安装的版本，我建议您从您的sources.list中删除此PPA，因为它在描述中明确指出：

PPA description

Backports of GNOME packages. This is for my personal use. Don't expect anything here to work properly.

资料来源：

http://packages.ubuntu.com/xenial/amd64/network-manager-gnome/download

如何删除PPA？

https://launchpad.net/~vascofalves/+archive/ubuntu/gnome-backports

1. 无论如何，都从更新软件包列表开始。

   sudo apt-get update
   

   请注意，任何进一步的操作都可能会删除重要的网络程序包，但是您可能会遇到复杂的非网络情况。因此，在阅读其余步骤之前，请注意不要删除任何内容。

2. 如有可能，请使用aptitude。

   sudo aptitude
   

   （如果已安装）。与apt-get或您使用的任何GUI相比，它在解决依赖项方面确实更具攻击性。看一下联机帮助页，但是要快速入门，请按几次“ b”（代表Breaked），可以看到所有损坏的软件包。然后只需按一下“ g”（代表go），然后查看有关建议解决方案的软件包树。如果解决方案不是删除整个系统：）（超过几个deb），则可以将其与第二个“ g”一起应用。

3. 如果您没有能力或上述修复没有成功，请通过以下方法修复所有损坏的包装：

   sudo apt-get -f install
   

4. 如果仍然没有运气，则需要手动修复它，这需要花费更多时间来解决问题。在这种情况下，请先查看hold软件包：

   apt-mark showhold 
   

   要么

   dpkg --get-selections | grep hold
   

   然后查看损坏的包装：

   dpkg -l | grep ^..r 
   

   然后解开使您生气的破碎的那一个：

   sudo apt-mark unhold package_name
   

   并尝试

   sudo apt-get -f install
   

   再次。

最后，您可以尝试安装aptitude并将其用于安装所需的软件包。如果这不成功，请向您的问题中添加保留和损坏的软件包列表，因为您可能确实有损坏的依赖项。

在收到问题作者的其他信息后进行编辑

看来您已经安装了一些PPA，该版本相对于当前的最新稳定版本（在16.04中）1.2.0-0ubuntu0.16.04 具有更高的优先级，版本1.2.4-0ubuntu2〜ubuntu16.04.1〜ppa1的network-manager-gnome软件包.4。较新的软件包可能来自某些gnome-backport仓库，例如gnome-backport仓库，例如this。

两种继续的方法...

1. 还原Gnome的稳定版本（针对16.04）
2. 查找其他任何PPA中缺少的软件包

对于场景1：我的下一个建议是通过运行然后以斜杠（“ /”）进行交互，以交互方式启动智能，sudo aptitude然后在搜索字段network-manager-gnome中输入并输入。选择包后，请按Enter打开它，并使用箭头/ pgdown进入信息页面的底部。您可以在此处选择安装正式版本“ 1.2.0-0ubuntu0.16.04.4”-选择它，然后按加号（+）。这将触发aptitude软件包依赖解析器，并尝试为您提供解决方案。万一hedaer变红，这意味着存在一些破坏性的依赖关系-多次按“ b”进行检查...

不幸的是，该解决方案很可能将删除所有向后移植的Gnome工作人员。然后尝试通过aptitude安装任何其他软件包，以提前了解可能会遇到的麻烦...

对于场景2：我们首先需要知道您正在使用的backport存储库...可能不是此库，因此如注释讨论中所建议-提供以下内容：

egrep -v '^#|^ $' /etc/apt/sources.list /etc/apt/sources.list.d/ 

和

egrep Pin-Priority /etc/apt/preferences /etc/apt/preferences.d/*

通过使用aptitude重新安装或安装network-manager-gnome可以解决此问题，在该问题上，我被告知可以解决依赖关系或不进行任何更改。解决依赖关系解决了问题（使它们降级）。