The Phabricator-jenkins plugin from GitHub - uber/phabricator-jenkins-plugin: Jenkins plugin to integrate with Phabricator, Harbormaster, and Uberalls can take lint input and report it to Harbormaster. However, for unknown reasons, it does not take the output of “arc lint --output json”, instead accepting one line per message. See https://github.com/uber/phabricator-jenkins-plugin/issues/255.
This could be changed on the plugin-side, however it’d be a breaking change there (and a PR went nowhere in 2018). On the arcanist side, it’s rather trivial to add a specific printer. I’ve done so in a local extension for 0 A.D.'s usage (see here).
This is basically a feature request → would it be acceptable to add a new printing format that outputs one line per message, as the jenkins plugin expects?