jboner/akka — comment on commit 4b8f11ea92ab3fb4809e2ca84b11ac93771477bb
File: akka-actor/src/main/scala/akka/actor/ActorSystem.scala line 55
By patriknw:

Thanks, I read the docs and was puzzled, because it is really this way we built up the config. We even add the reference afterwards, i.e. it is impossible to use the withFallbacks. If you fix the issue I think you should remove withFallbacks.
More realistic is foo {a =1} withFallback foo {b = 2} with Fallback foo {a = 0, b = 0, c = 0} which should become foo {a = 1, b = 2, c = 0}
Clearing (nulling) isn't something I would have expect working at all.