模式丢失 - Unity Tweak Tool

Question

我理解这一点非常相似，这个问题与这一个，但没有出现为我工作的答案。尝试安装这些问题中提到的软件包时，apt-get 会抛出以下错误消息：

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.
 unity-webapps-service : Depends: webapp-container
E: Unable to correct problems, you have held broken packages.

当我尝试安装那里提到的依赖项时，我发现越来越多的依赖项。当我选择“修复损坏的包”时，Synaptic 包管理器会给出错误消息。我怎样才能解决这个问题？

提前致谢，如果您需要更多信息，请发表评论。

更新：运行apt-cache policy webapp-container unity-webapps-service给出了以下结果：

webapp-container:
  Installed: (none)
  Candidate: 0.23+14.04.20140428-0ubuntu1
  Version table:
     0.23+14.04.20140428-0ubuntu1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
     0.23+14.04.20140414-0ubuntu1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
unity-webapps-service:
  Installed: (none)
  Candidate: 2.5.0~+14.04.20140409-0ubuntu1
  Version table:
     2.5.0~+14.04.20140409-0ubuntu1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

更新 2：版本信息：

LSB Version:    core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch:core-4.1-amd64:core-4.1-noarch:security-4.0-amd64:security-4.0-noarch:security-4.1-amd64:security-4.1-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 14.04.2 LTS
Release:    14.04
Codename:   trusty

更新 3：尝试unity-webapps-service使用 aptitude 而不是 apt-get进行安装时：

The following NEW packages will be installed:
  liboxideqt-qmlplugin{a} liboxideqtcore0{a} liboxideqtquick0{ab} 
  libqt5feedback5{a} libqt5multimedia5{ab} libqt5organizer5{ab} 
  libqt5positioning5{ab} libunity-webapps0{a} 
  qtdeclarative5-dialogs-plugin{ab} 
  qtdeclarative5-privatewidgets-plugin{ab} 
  qtdeclarative5-qtfeedback-plugin{a} 
  qtdeclarative5-ubuntu-ui-extras-browser-plugin{a} 
  qtdeclarative5-ubuntu-ui-toolkit-plugin{ab} unity-webapps-qml{a} 
  unity-webapps-service webapp-container{ab} webbrowser-app{ab} 
0 packages upgraded, 17 newly installed, 0 to remove and 0 not upgraded.
Need to get 26.6 MB of archives. After unpacking 103 MB will be used.
The following packages have unmet dependencies:
 webapp-container : Depends: qtdeclarative-abi-5-2-1 which is a virtual package.
 libqt5organizer5 : Depends: qtbase-abi-5-2-1 which is a virtual package.
 qtdeclarative5-dialogs-plugin : Depends: qtbase-abi-5-2-1 which is a virtual package.
                                 Depends: qtdeclarative-abi-5-2-1 which is a virtual package.
 webbrowser-app : Depends: qtdeclarative-abi-5-2-1 which is a virtual package.
 qtdeclarative5-privatewidgets-plugin : Depends: qtbase-abi-5-2-1 which is a virtual package.
 libqt5multimedia5 : Depends: qtbase-abi-5-2-1 which is a virtual package.
 libqt5positioning5 : Depends: qtbase-abi-5-2-1 which is a virtual package.
 liboxideqtquick0 : Depends: qtdeclarative-abi-5-2-1 which is a virtual package.
 qtdeclarative5-ubuntu-ui-toolkit-plugin : Depends: qtbase-abi-5-2-1 which is a virtual package.
                                           Depends: qtdeclarative-abi-5-2-1 which is a virtual package.
The following actions will resolve these dependencies:

      Keep the following packages at their current version:           
1)      liboxideqt-qmlplugin [Not Installed]                          
2)      liboxideqtcore0 [Not Installed]                               
3)      liboxideqtquick0 [Not Installed]                              
4)      libqt5feedback5 [Not Installed]                               
5)      libqt5multimedia5 [Not Installed]                             
6)      libqt5organizer5 [Not Installed]                              
7)      libqt5positioning5 [Not Installed]                            
8)      libunity-webapps0 [Not Installed]                             
9)      qtdeclarative5-dialogs-plugin [Not Installed]                 
10)     qtdeclarative5-privatewidgets-plugin [Not Installed]          
11)     qtdeclarative5-qtfeedback-plugin [Not Installed]              
12)     qtdeclarative5-ubuntu-ui-extras-browser-plugin [Not Installed]
13)     qtdeclarative5-ubuntu-ui-toolkit-plugin [Not Installed]       
14)     unity-webapps-qml [Not Installed]                             
15)     unity-webapps-service [Not Installed]                         
16)     webapp-container [Not Installed]                              
17)     webbrowser-app [Not Installed]                                



Accept this solution? [Y/n/q/?]

更新4：输出sudo apt-get install qtdeclarative-abi-5-2-1：

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package qtdeclarative-abi-5-2-1 is a virtual package provided by:
  libqt5qml5 5.2.1-3ubuntu15.1 [Not candidate version]
  libqt5qml5 5.2.1-3ubuntu15 [Not candidate version]

E: Package 'qtdeclarative-abi-5-2-1' has no installation candidate

的输出sudo apt-get install unity-webapp-container：

Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package unity-webapp-container

更新 5：输出apt-cache policy libqt5qml5：

libqt5qml5:
  Installed: 5.3.0-3ubuntu13~trusty1
  Candidate: 5.3.0-3ubuntu13~trusty1
  Version table:
 *** 5.3.0-3ubuntu13~trusty1 0
        500 http://ppa.launchpad.net/mscore-ubuntu/mscore-stable/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status
     5.2.1-3ubuntu15.1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
     5.2.1-3ubuntu15 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

的输出sudo apt-get install webapp-container：

Reading package lists... Done
Building dependency tree       
Reading state information... 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.
 webapp-container : Depends: qtdeclarative-abi-5-2-1
                    Depends: unity-webapps-qml but it is not going to be installed
                    Depends: webbrowser-app (= 0.23+14.04.20140428-0ubuntu1)
E: Unable to correct problems, you have held broken packages.

Answer 1

我会冒险并留下回应。

一个主要问题似乎是 PPA ppa:mscore-ubuntu/mscore-stable。使用此 PPA，您无法使用所需的版本libqt5qml5

因此，使用以下命令删除 PPA。

sudo ppa-purge ppa:mscore-ubuntu/mscore-stable

在那之后

sudo apt-get install -f

最后

sudo apt-get install unity-webapps-service

问题出在哪儿？

该命令apt-cache policy libqt5qml5返回以下内容。PPA ppa:mscore-ubuntu/mscore-stable 安装了较新的版本 (5.3.0)，libqt5qml5 但qtdeclarative-abi-5-2-1需要准确的版本 5.2.1。

libqt5qml5:
  Installed: 5.3.0-3ubuntu13~trusty1
  Candidate: 5.3.0-3ubuntu13~trusty1
  Version table:
 *** 5.3.0-3ubuntu13~trusty1 0
        500 http://ppa.launchpad.net/mscore-ubuntu/mscore-stable/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status
     5.2.1-3ubuntu15.1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
     5.2.1-3ubuntu15 0
        500 http://gb.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

副作用

清除 PPA 会降级 PPA 安装的软件包。如果无法降级，因为一个包只存在于这个 PPA 中，该包将被删除。删除后，该软件包的配置文件仍然存在于您的系统中。