latest skopeo and oci image-tools don't seem to match up

[dcapwell]

Testing out skopeo and image-tools but having a hard time getting them to work together.

[root@ed78599d315d deleteme]# skopeo copy docker://centos oci:centos-oci
Getting image source signatures
Copying blob sha256:45a2e645736c4c66ef34acce2407ded21f7a9b231199d3b92d6c9776df264729
 67.13 MB / 67.13 MB [=========================================================]
Copying config sha256:67591570dd29de0e124ee89d50458b098dbd83b12d73e5fdaf8b4dcbd4ea50f8
 0 B / 2.25 KB [---------------------------------------------------------------]
Writing manifest to image destination
Storing signatures
[root@ed78599d315d deleteme]# oci-image-validate centos-oci/
centos-oci/: validation failed: mediaType: mediaType is required
[root@ed78599d315d deleteme]# oci-image-validate --ref latest centos-oci/
centos-oci/: validation failed: mediaType: mediaType is required

Any idea what is going on? Running this inside docker with the following Docker file

# Followed https://www.digitalocean.com/community/tutorials/how-to-install-go-1-7-on-centos-7
FROM centos:centos7

# Setup golang
RUN (cd /usr/local; curl -L 'https://storage.googleapis.com/golang/go1.7.linux-amd64.tar.gz' | tar -xzf -)

# Setup go source locations
RUN \
  mkdir -p /opt/golang/ $HOME/bin && \
  echo "export PATH=$PATH:/usr/local/go/bin" >> /etc/bashrc && \
  echo "export GOBIN=$HOME/projects/bin" >> /etc/bashrc && \
  echo "export GOPATH=$HOME/projects/src" >> /etc/bashrc

ENV PATH    $PATH:/usr/local/go/bin:$HOME/bin
ENV GOBIN   $HOME/projects/bin
ENV GOPATH  $HOME/projects/src

# install dependencies
RUN \
  yum groupinstall -y "development tools" && \
  yum install -y tree git make gpgme-devel libassuan-devel device-mapper-devel btrfs-progs-devel libseccomp-devel which

# install skopeo
# https://github.com/projectatomic/skopeo
RUN \
  git clone https://github.com/projectatomic/skopeo $GOPATH/src/github.com/projectatomic/skopeo && \
  cd $GOPATH/src/github.com/projectatomic/skopeo && \
  make binary-local && \
  mv skopeo $HOME/bin/ && \
  mkdir -p /etc/containers && \
  cp default-policy.json /etc/containers/policy.json

# install OCI image tools
# https://github.com/opencontainers/image-tools/
RUN \
  git clone https://github.com/opencontainers/image-tools.git $GOPATH/src/github.com/opencontainers/image-tools && \
  cd $GOPATH/src/github.com/opencontainers/image-tools && \
  make tools && \
  mv oci-* $HOME/bin

# install runC
# https://github.com/opencontainers/runc
run \
  git clone https://github.com/opencontainers/runc.git $GOPATH/src/github.com/opencontainers/runc && \
  cd $GOPATH/src/github.com/opencontainers/runc && \
  make && \
  mv runc $HOME/bin

[runcom]

This is an issue with upstream oci-image-tool. oci-image-tool uses image-spec v1.0.0-rc3 whether we're tracking image-spec master and master contains opencontainers/image-spec#531 which drops mediaType at the manifest level.
As soon as image-spec reaches v1.0.0 we'll freeze the spec vendored and everything should work.