I can confirm that on a clean install of RHEL6, this package does not work. In addition to the ansible-vault issue, it also does not run at all ("ImportError: No module named jinja2.exceptions"). The issue can be resolved by installing python-jinja2 (rather than python-jinja2-26), which tells me that the old patch to make ansible use jinja 2.6 is no longer effective.

I think the fix for #1494640 should be applied to the Ansible 2.3 spec and leave this as another change, unless it's immediately obvious to someone else how to get ansible to pickup jinja 2.6 properly.

The bug with the syntax error is fixed, but this version seems to have a new problem where I have to wipe out my cache before every use (get errors with "No such file or directory" for the source files being copied into the chroot).