我在我的VirtualBox中安装了ubuntu-14.04.4-server-amd64.iso，然后我用某种方式来获取它的rootfs。之后我可以让rootfs创建我的docker image.Dockerfile如下：
FROM scratch
COPY rootfs /
RUN chmod u+s /usr/bin/sudo && chmod u+s /bin/mount && chmod u+s /bin/umount
我启动我的docker容器，然后我安装了一些工具，比如minicom，wget ...，但是错误，以下是错误消息：
root@20ca319c51e6:~$ apt-get install minicom
Reading package lists... Done
Building dependency tree
Reading state information... Done
minicom is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up libpam-systemd:amd64 (204-5ubuntu20.19) ...
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused
invoke-rc.d: unknown initscript, /etc/init.d/systemd-logind not found.
runlevel:/var/run/utmp: No such file or directory
dpkg: error processing package libpam-systemd:amd64 (--configure):
subprocess installed post-installation script returned error exit status 100
Errors were encountered while processing:
libpam-systemd:amd64
E: Sub-process /usr/bin/dpkg returned an error code (1)
我也试着＆＃34; apt-get update; apt-get upgrade＆＃34;但是也得到相同的错误信息， 我该怎么办。需要你的帮助！谢谢大家:)）