Failed docker build at RUN mkdir in Dockerfile

Hi all,

I try to run docker build on CircleCI.
Pull base image from repo, and build docker image from the base image.

Then, I run into the problem

Step 9 : RUN mkdir -p /data
 ---> Running in 986b4fa3a198
The command '/bin/sh -c mkdir -p /data' returned a non-zero code: 255

Why this simple mkdir command fails?
Is this related to the problem about btrfs?

regards,