Our npm-test jobs currently run on (relatively) plain Trusty instances which come with Node 0.10, which is getting old. There's been Node 0.12 (stable), Node 4 (stable, LTS) and Node 5 (stable) since then.
I'm running into various package upgrades failing because indirect dependencies are increasingly dropping support for Node 0.10.
Either we need to upgrade (backport) the package, or run these on Jessie perhaps with Node 4.