I'm using systemd 210 from rawhide on Fedora 20 x86_64.  I've created a container with i686 yum packages installed.  When attempting to run a systemd-nspawn command with "-u <user>" specified, I get the following error:

Spawning container mycontainer-i686 on /srv/mycontainer-i686. Press ^] three times within 1s to abort execution.
get_user_creds() failed: Success

Container mycontainer-i686 failed with error code 1.

This does not happen if the container has x86_64 yum packages installed instead.

Steps to Reproduce:
-------------------

$ su -
$ mkdir /srv/mycontainer-i686
$ mkdir -p /srv/mycontainer-i686/etc/yum/vars
$ echo i386 > /srv/mycontainer-i686/etc/yum/vars/basearch
$ echo i686 > /srv/mycontainer-i686/etc/yum/vars/arch
$ yum -y --releasever=20 --nogpg --installroot=/srv/mycontainer-i686 --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal
$ systemd-nspawn -D /srv/mycontainer-i686 adduser jail
$ systemd-nspawn -D /srv/mycontainer-i686 passwd -d jail
$ systemd-nspawn -u jail -D /srv/mycontainer-i686 whoami

I also tried installing systemd from rawhide into the container, but still get the same error.