Bug 1639873 allows backfilling tasks that use test manifests. This can be achieved via a Custom action from the Treeherder UI.

We can now replace the current backfill with the new one.

The backfill action will support both tasks with manifest based scheduling and without.

This adds the support for backfilling of manifest scheduled tasks while
preserving the existing features (e.g. schedule a specific test path).

We remove the temporary new-backfill action.

This optional mode to specify a test path when backfilling has been broken for a while
and is not being used to make it worth fixing. It is a mode
originally designed to be used with the test-verify tasks.

Sheriffs, when this code lands on autoland (which I will land early on my day) we will need to pay close attention to the backfill action from that point on.

I've tested this with some hacks on Try, however, I will need your close attention and check quickly with me the day we land this so we can back it out quickly if necessary.

This change affects the backfill request from Treeherder's UI.

The NI is only to ensure you see this comment. I will check on Riot before landing.

The first push contains the code in this bug.
The second push is the state of mozilla-central, thus, backfilling with the new code can schedule over pushes with the old code (This makes sense since the backfill-task action is landed since last week).

So far it seems working.

I'm seeing Bk and backfill-task actions.

I see bc6 and bc6-revision-bk tasks.

This seems to work so far.

If filtering tasks gets annoying feel free to ask the team to promote this change as I'm away tomorrow:
https://github.com/mozilla/treeherder/commit/50005b1b13d1fa3793c61d94a75d2970090d46b3

https://hg.mozilla.org/mozilla-central/rev/c96d73d17b9a
https://hg.mozilla.org/mozilla-central/rev/d048d01665a5