https://wiki.mozilla.org/ReleaseEngineering/ThunderbirdTryServer made us believe that we can push to try-comm-central using ../mach try <TryChooserSyntaxOptions>. That is not the case. If one uses that command, at worst a job is pushed to M-C try repository.

I don't know whether it ever worked, but I believe Tom was using it a while back. So let's assume that it broke at some stage.

It may have worked at some point in the past, but it never has for me (since 2018-08-01 or so).

I know various workarounds exist, and I have a few of my own I'm happy to share. But, yes, this should work so things like mach try fuzzy work. I'll see what I can do with it since it will make things easier for new contributors.\

Making this change will get 'mach try empty' to run, assuming you have the configured your checkout with the push-to-try extension as documented at https://wiki.mozilla.org/ReleaseEngineering/ThunderbirdTryServer.

That breaks the syntax chooser though, since it imports the "build" variable from push.py. And really nothing else works then either. There's a lot that depends on the 'fact' that the repository you are pushing is a clone of mozilla-central (or one of its derivatives).

For example, the task generation code that 'mach try fuzzy' relies on: (edited for brevity)

root = build.topsrcdir
root = os.path.join(root, 'taskcluster', 'ci')
generator = TaskGraphGenerator(root_dir=root, parameters=params)

If we wanted that to work for Thunderbird, I think "all" we need to do is change that first line to something like

root = os.path.join(build.topsrcdir, 'comm')

But there's other places where this won't work so well. Suggestions welcome.

But there's other places where this won't work so well. Suggestions welcome.