bug#15571: -su: 31: export: : bad variable name

[rufai mustapha]

I tried entering into my chroot from acer c7 chromebook using the command
line
"shell"
"sudo startunity"
then, I got the error I made the subject. Is there any way to solve this.
Am a beginner, and I use ubuntu 12.04 on a 32 bit.