Hilary James Oliver

Title changed to reflect the growing consensus on this issue.

I would be keen to up the priority of this one, as it comes up in making site-portable suites too. However, we're not exactly short of things to work on...

[meeting] - need to support `+=` and `-=` (list and string) - and obliteration of items (not just unsetting) - e.g. for environment vars and job directives - after this...

IMO this would be useful, but we still have many higher priorities.

This new block is the cause, but I haven't figured out exactly what's going on: https://github.com/cylc/cylc-flow/blob/a965b918a57e89e9e79119a59cfce2686c84674e/cylc/flow/scheduler.py#L1089-L1112

Ah, some progress. It's because the same job gets submitted twice! (Not double-handling of queued commands during reload as I initially thought). It only happens if the task state hasn't...

Can we just leverage the `cylc stop --now` (but not `--now --now`) code, for the abort shutdown? ``` stop -n, --now Shut down without waiting for active tasks to complete....

> Eh? 1/z only depends on 1/a:1, 1/a:2 & 1/a:3? > > And why are they in pairs, is there a duplicate method call? A double count, not a duplicate...

It sure is wild out there.

@dwsutherland this is now my main focus for review - are you working on conflict resolution, post `cylc set` merge? Ping me if you need any help understanding the changes...