Phabricator has technically supported "postponed" lint and unit tests for a long time, although this support has never been documented or recommended and no upstream code has ever used it.
This was an ancient hack to get some approximation of CI support. Harbormaster is now capable of providing that support in a more powerful way, and anything using postponed lint and unit tests should move to Harbormaster. Specifically, these things have changed in HEAD:
- The `differential.finishpostponedlinters` API call no longer exists.
- The `differential.updateunitresults` API call no longer exists.
- The `differential.setdiffproperty` API call no longer has special casing to handle lint in a special way.
- After D13868, Arcanist no longer recognizes the "postponed" statuses.
Generally, this means that lint and test engines which rely on the "postponed" mechanism will no longer function.
All of these mechanisms have been replaced by [[ https://secure.phabricator.com/book/phabricator/article/harbormaster/ | Harbormaster ]]. In particular, Harbormaster can trigger builds when revisions are created, and `harbormaster.sendmessage` permits external scripts to upload unit test and lint results.