无法升级到 Ubuntu 14.04

Question

当我尝试从 Ubuntu Gnome 13.10 升级到 Ubuntu 14.04 时，升级应用程序失败并显示以下消息：

Could not calculate the upgrade. 
An unresolvable problem occurred while calculating the upgrade.`

这是完整的日志：

$ cat /etc/issue
Ubuntu 13.10 \n \l
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo do-release-upgrade
Checking package manager
Reading package lists... Done    
Building dependency tree          
Reading state information... Done
Building data structures... Done 

Calculating the changes

Calculating the changes

Could not calculate the upgrade 

An unresolvable problem occurred while calculating the upgrade. 

This can be caused by: 
* Upgrading to a pre-release version of Ubuntu 
* Running the current pre-release version of Ubuntu 
* Unofficial software packages not provided by Ubuntu 

If none of this applies, then please report this bug using the 
command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. 


Restoring original system state

Aborting
Reading package lists... Done    
Building dependency tree          
Reading state information... Done
Building data structures... Done 

我错过了什么吗？或者这只是一个错误？

更新：我分析了日志文件，发现它do-release-upgrade在抱怨一些过时的包。

$ cat /var/log/dist-upgrade/main.log | grep Obsolete
2014-04-28 09:16:23,678 DEBUG Obsolete: flashplugin-nonfree-extrasound:i386 (..)

删除这些包后，我能够继续升级。

Answer 1

1. 查找/var/log将包含更多详细信息的发布升级程序日志文件。

2. 错误消息说明：

This can be caused by: ... * Unofficial software packages not provided by Ubuntu

那么，您是否安装了来自 PPA 的任何软件，或者您是否编辑过任何默认源？如果是这样，那可能就是问题所在。禁用任何 PPA 或其他第三方存储库，然后重试。如果它仍然不起作用，您可能需要实际卸载一些软件包或用官方存储库中的版本替换它们。