Hi, being the one who usually prepares the releases, i am currently standing in hands-off position until the time_t change is completed. The package tracker is still complaining bitterly about the current intermediate state.
Consider to re-open https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1062380 "libisoburn: NMU diff for 64-bit time_t transition" and/or to contact its submitter. Have a nice day :) Thomas