spark.blacklist.killBlacklistedExecutors doesn't work in YARN

I was trying out the new spark.blacklist.killBlacklistedExecutors on YARN but it doesn't appear to work. Everytime I get:

17/05/26 16:28:12 WARN BlacklistTracker: Not attempting to kill blacklisted executor id 4 since allocation client is not defined

Even though dynamic allocation is on. Taking a quick look, I think the way it creates the blacklisttracker and passes the allocation client is wrong. The scheduler backend is
not set yet so it never passes the allocation client to the blacklisttracker correctly. Thus it will never kill.