We were getting some subtle issues in fedora-minimal builds that
turned out to be because /var/run was not a symlink to /run.
Upon further investigation, it turns out that yum is creating a
/var/run directory for it's pid file when it starts working in the
empty chroot (which I verified by stracing it)
---
5905 stat("/home/ubuntu/tmp/dib-tmp/image.Ac4VZZsl/mnt/var/run", 0x7ffddffa0330) = -1 ENOENT (No such file or directory)
5905 mkdir("/home/ubuntu/tmp/dib-tmp/image.Ac4VZZsl/mnt/var/run", 0755) = 0
5905 open("/home/ubuntu/tmp/dib-tmp/image.Ac4VZZsl/mnt/var/run/yum.pid", O_WRONLY|O_CREAT|O_EXCL, 0644) = 6
---
Because this happens *before* we install "filesystem" (the package),
we mess up it's symlinking.
To work-around this, pre-install the trio of base packages (setup,
basesystem, filesystem) with rpm from outside the chroot.
Change-Id: I411b6ec9d91d95d3a0f98e76853086af3b70abe8
349e8db2f7