Bug#1010971:

[Ryan Tandy]

Control: reassign -1 slapd 2.5.12+dfsg-1
Control: affects -1 src:sssd
Control: forcemerge -1 1010678

Thanks Andreas for providing the additional details here. I'm aware of 
the problem and will upload openldap with a workaround ASAP. I had not 
seen Dave's MR for debconf, though; thanks for that.

Merging with #1010678. I had also opened #1010677 against debhelper, 
which I guess I will close once debconf is fixed.