What is the dict.cc entry : etw. hätte gemacht worden sein müssen?

Question

Here is this dict.cc entry that i stumbled across, it appears to be wrong, to my knowledge that should be:

1) Das hätte gemacht werden müssen – That would have had to have been done (but it wasn’t)

or

2) Das müsste gemacht worden sein – That would have had to have been done, was bound to have been done before xyz time, in order for something to be the case.

so what is dict.cc's 3) "etw hätte gemacht worden sein müssen"... Is this correct? is this another tense?

I think maybe it is wrong.

Unless this is correct and the difference between 1) and 3) would be perhaps:

1) That would have had to have been in the process of being done

3) That would have had to have already been done, before xyz happens

So whats the difference in the german phrases: "das hätte gemacht werden müssen" and "das hätte gemacht worden sein müssen"

Answer 1

Nice tricky question.

Das hätte gemacht werden müssen

That should have been in the process of being done by the time we're referring to. No statement is made whether the deadline for finishing the work is in the past or future. Most probably it hasn't been started yet, though.

Das müsste gemacht worden sein

The process of "making" should have been finished by the time we're referring to. And the reference is from today. We don't know whether it's been done or not. Deadline for finishing can be in the past or future.

Hätte gemacht worden sein müssen

The process of "making" should have been finished by the time we're referring to. And the reference is from yesterday - We know it hasn't been done. Deadline for finishing thus was in the past.

IMHO, the entry is OK.

Answer 2

Those a two different flavours of past tense:

"Das hätte gemacht werden müssen." -->
It had to be done, but wasn´t; so now we have a problem.

"Das hätte gemacht worden sein müssen." -->
It had to be done, but wasn´t; so then we had a problem.