CuBox Ubuntu Trusty Docker 1.8.1 Build Error

I realize Docker folks may still be working on ARM 32bit support, but thought I would feedback an error I got during attempting to make 1.8.1.
I was attempting a build compiling directly on the CuBox i.mx6 platform as suggested by Uli Middelberg’s excellent work on supporting various ARM devices.

$ git clone -b ‘v1.8.1’ --single-branch https://github.com/docker/docker.git
$ sudo make build


Step 14 : RUN curl -sSL …
2015/08/25 16:17:23 finalize namespace drop capabilities operation not permitted
2015/08/25 18:17:23 The command [/bin/sh -c curl -sSL https://golang.org/dl/go${GO_VERSION}.src.tar.gz | tar -v -C /usr/local -xz && mkdir -p /go/bin] returned a non-zero code: 1
make: *** [build] Error 1