我有一台 HP EliteBook 2540p。我想将我的 Ubuntu 16.04 升级到更新版本。我发现我需要升级到 18.04 才能升级到 20.04。
我通过使用以下命令更新系统和升级软件和软件包来尝试推荐的过程：
sudo apt update && sudo apt upgrade
Hit:1 http://archive.canonical.com/ubuntu xenial InRelease
Hit:2 http://ppa.launchpad.net/canonical-chromium-builds/stage/ubuntu xenial InRelease
Hit:3 http://repo.mysql.com/apt/ubuntu xenial InRelease
Hit:4 http://packages.microsoft.com/repos/code stable InRelease
Ign:5 http://repo.vivaldi.com/stable/deb stable InRelease
Hit:6 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:7 http://ma.archive.ubuntu.com/ubuntu xenial InRelease
Get:8 http://security.ubuntu.com/ubuntu xenial-security InRelease [109 kB]
Hit:9 http://ppa.launchpad.net/clipgrab-team/ppa/ubuntu xenial InRelease
Hit:10 http://repo.vivaldi.com/stable/deb stable Release
Get:11 http://ma.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
Get:12 https://download.docker.com/linux/ubuntu xenial InRelease [66.2 kB]
Hit:13 http://ppa.launchpad.net/nathan-renniewaldock/flux/ubuntu xenial InRelease
Hit:14 https://deb.opera.com/opera-stable stable InRelease
Hit:15 https://brave-browser-apt-release.s3.brave.com xenial InRelease
Hit:16 https://brave-browser-apt-dev.s3.brave.com xenial InRelease
Hit:17 http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu xenial InRelease
Hit:18 https://brave-browser-apt-beta.s3.brave.com xenial InRelease
Get:19 https://repo.skype.com/deb stable InRelease [4,502 B]
Hit:20 https://brave-browser-apt-nightly.s3.brave.com xenial InRelease
Hit:21 http://ppa.launchpad.net/noobslab/indicators/ubuntu xenial InRelease
Hit:22 https://esm.ubuntu.com/infra/ubuntu xenial-infra-security InRelease
Get:23 http://ma.archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]
Hit:24 https://deb.nodesource.com/node_5.x xenial InRelease
Hit:25 http://ppa.launchpad.net/ondrej/php/ubuntu xenial InRelease
Hit:26 https://esm.ubuntu.com/infra/ubuntu xenial-infra-updates InRelease
Hit:27 http://ppa.launchpad.net/remmina-ppa-team/remmina-next/ubuntu xenial InRelease
Hit:29 http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu xenial InRelease
Hit:30 https://packagecloud.io/AtomEditor/atom/any any InRelease
Hit:31 https://packagecloud.io/shiftkey/desktop/any any InRelease
Err:19 https://repo.skype.com/deb stable InRelease
The following signatures were invalid: KEYEXPIRED 1624268195 KEYEXPIRED 1624268195 KEYEXPIRED 1624268195
Hit:32 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease
Reading package lists... Done
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: GPG error: https://repo.skype.com/deb stable InRelease: The following signatures were invalid: KEYEXPIRED 1624268195 KEYEXPIRED 1624268195 KEYEXPIRED 1624268195
E: The repository 'https://repo.skype.com/deb stable InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
我想我无法获得我需要的所有更新和升级，而且我不知道是什么问题。
之后我尝试了这个命令来检查可用的版本：
$ sudo do-release-upgrade -c
Checking for a new Ubuntu release
New release '18.04.6 LTS' available.
Run 'do-release-upgrade' to upgrade to it.
看起来它正在工作，但是当我尝试升级命令时，它不起作用：
$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
我不知道问题是什么。
