警告：root：文件’precise.tar.gz.gpg’缺失
首先，我尝试通过更新管理器GUI从11.10安装12.04升级后，没有更多的安装更新和重新启动后，但所有这一切都会说下载发布升级工具，然后它就是其他任何东西。
所以我尝试从终端\命令行运行它
brown@brown-Ubuntu:~$ update-manager -d brown@brown-Ubuntu:~$ do-release-upgrade Checking for a new ubuntu release Err Upgrade tool signature Connection failed Get:1 Upgrade tool [5612 kB] Fetched 5612 kB in 0s (0 B/s) WARNING:root:file 'precise.tar.gz.gpg' missing Failed to fetch Fetching the upgrade failed. There may be a network problem. 有人可以帮帮我吗。
所以我找到了sorta解决方法：
- 打开/ var / lib / update-manager / meta-release，找到字符串：
Dist: precise Name: Precise Pangolin Version: 12.04 LTS Date: Thu, 26 Apr 2012 12:04:00 UTC Supported: 1 Description: This is the 12.04 LTS release Release-File: http://archive.ubuntu.com/ubuntu/dists/precise/Release ReleaseNotes: http://archive.ubuntu.com/ubuntu/dists/precise/main/dist-upgrader-all/current/ReleaseAnnouncement ReleaseNotesHtml: http://archive.ubuntu.com/ubuntu/dists/precise/main/dist-upgrader-all/current/ReleaseAnnouncement.html UpgradeTool: http://archive.ubuntu.com/ubuntu/dists/precise/main/dist-upgrader-all/current/precise.tar.gz UpgradeToolSignature: http://archive.ubuntu.com/ubuntu/dists/precise/main/dist-upgrader-all/current/precise.tar.gz.gpg
- 下载UpgradeTool和UpgradeToolSignature文件
- 将它们上传到任何其他Web服务器并修改相应的字符串（我猜即使file：///也可以）
- sudo do-release-upgrade
为我工作，希望也会帮助你。 祝好运！
-
修改文件“/ var / lib / update-manager / meta-release”将“archive.ubuntu.com”替换为“old-releases.ubuntu.com”
-
运行“do-release-upgrade”
-
当它暂停“第三方来源禁用”时，打开另一个ssh会话以修改“/etc/apt/sources.list”并将“archive.ubuntu.com”替换为“old-releases.ubuntu.com”
-
继续升级