I'm attempting to figure out whether or not we have a buildbot in the Buildbot fleet that will cover this test case.

Based on the pre-merge CI run, it seems Ubuntu 14.04 is too old to include the required kernel headers.

However, it looks like RHEL/CentOS are also currently still missing the userspace changes to fully enable AF_VSOCK support (as the Red Hat backport flow appears to have gone through the dedicated hypervisor variant first): https://bugzilla.redhat.com/show_bug.cgi?id=1315822

So it's looking to me like we're going to need either a recent Fedora, a non-LTS Ubuntu, or a Debian 9 system to be confident we have the right headers available.