在从16.04升级到18.04的过程中，在最后阶段它显示了以下信息：
按下[ENTER]键
现在当我执行apt update / apt upgrade命令时，会出现以下提示信息：
在https://packages.ubuntu.com/bionic/libs/中查看，无论如何，对于18.04的libsystemd0显示如下。所以我不确定为什么系统认为依赖关系应该是229-4ubuntu21.31。
apt upgrade 结束时还会显示以下内容：
当我运行这个时，我得到的结果是：
显然发生了一些非常可怕的事情。
我有点力不从心，希望能得到一些指导/下一步的建议。
谢谢。
添加：按照NOrbert的要求输出。
The upgrade has completed but there were errors during the upgrade
process.
To continue please press [ENTER]
按下[ENTER]键
现在当我执行apt update / apt upgrade命令时，会出现以下提示信息：
The following packages have unmet dependencies:
systemd : Depends: libsystemd0 (= 229-4ubuntu21.31) but 237-3ubuntu10.48 is installed
在https://packages.ubuntu.com/bionic/libs/中查看，无论如何，对于18.04的libsystemd0显示如下。所以我不确定为什么系统认为依赖关系应该是229-4ubuntu21.31。
libsystemd0 (237-3ubuntu10.38 [amd64, i386], 237-3ubuntu10 [arm64, armhf, ppc64el, s390x]) [security]
systemd utility library
apt upgrade 结束时还会显示以下内容：
You might want to run 'apt-get -f install' to correct these.
当我运行这个时，我得到的结果是：
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
cgmanager libargon2-0 libcryptsetup12 libgd3 libip4tc0 libjson-c3 libkadm5clnt-mit9 libluajit-5.1-2 libluajit-5.1-common libvpx3 libxpm4 nginx-common
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
upstart
Suggested packages:
graphviz upstart-monitor
The following packages will be REMOVED:
init libpam-systemd systemd systemd-shim systemd-sysv ubuntu-standard
The following NEW packages will be installed:
upstart
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
init systemd-sysv (due to init)
0 upgraded, 1 newly installed, 6 to remove and 0 not upgraded.
1 not fully installed or removed.
Need to get 0 B/392 kB of archives.
After this operation, 18.1 MB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase 'Yes, do as I say!'
显然发生了一些非常可怕的事情。
我有点力不从心，希望能得到一些指导/下一步的建议。
谢谢。
添加：按照NOrbert的要求输出。
nexargi@server-02:~$ apt-cache policy systemd libsystemd0 init systemd-sysv
systemd:
Installed: 229-4ubuntu21.31
Candidate: 229-4ubuntu21.31
Version table:
*** 229-4ubuntu21.31 500
500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
100 /var/lib/dpkg/status
229-4ubuntu21.27 500
500 http://us.archive.ubuntu.com/ubuntu xenial-security/main amd64 Packages
229-4ubuntu4 500
500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
libsystemd0:
Installed: 237-3ubuntu10.48
Candidate: 237-3ubuntu10.48
Version table:
*** 237-3ubuntu10.48 100
100 /var/lib/dpkg/status
229-4ubuntu21.31 500
500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
229-4ubuntu21.27 500
500 http://us.archive.ubuntu.com/ubuntu xenial-security/main amd64 Packages
229-4ubuntu4 500
500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
init:
Installed: 1.29ubuntu4
Candidate: 1.29ubuntu4
Version table:
*** 1.29ubuntu4 500
500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
100 /var/lib/dpkg/status
1.29ubuntu1 500
500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
systemd-sysv:
Installed: 229-4ubuntu21.31
Candidate: 229-4ubuntu21.31
Version table:
*** 229-4ubuntu21.31 500
500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
100 /var/lib/dpkg/status
229-4ubuntu21.27 500
500 http://us.archive.ubuntu.com/ubuntu xenial-security/main amd64 Packages
229-4ubuntu4 500
500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
根据NOrbert的要求，编辑以包含到Pastebin的链接： @NOrbert 请注意，这些是在恢复16.04后立即获取的。即它们代表任何版本升级之前16.04的状态。
grep -r ^deb /etc/apt --include=*.list https://pastebin.com/85qJeYws
apt-cache policy https://pastebin.com/q8S47v1e
dpkg -l https://pastebin.com/Zp999iuF
apt-cache policy systemd libsystemd0 init systemd-sysv命令的输出添加到问题中。 - N0rbert