I've found this question:

https://askubuntu.com/q/337473/32239

which is marked as a duplicate of: 

[How to specify a control file in dh_gencontrol?](https://askubuntu.com/q/337504/32239)

But it turns out to be a deleted question.

Should the first one be reopened? Is there a mechanism that could prevent such situation? Because to me without the original question it makes no sense to leave the "marked as duplicate".