在Docker容器中安装工具时出错

我在我的VirtualBox中安装ubuntu-14.04.4-server-amd64.iso，然后使用某种方式获取它的rootfs。 之后，我可以rootfs创build我的dockerimage.the Dockerfile如下：

FROM scratch COPY rootfs / RUN chmod u+s /usr/bin/sudo && chmod u+s /bin/mount && chmod u+s /bin/umount 

我开始我的docker容器，然后我安装一些工具，如minicom，wget …，但错误，以下是错误信息：

 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) 

我也尝试“apt-get update; apt-get upgrade”，但是也得到同样的错误信息，我该怎么做。需要你帮忙！ 感谢所有:)