Version 2.4.0-2 of libbpp-popgen is marked for autoremoval from testing on Tue 18 Sep 2018. It is affected by #897782. The removal of libbpp-popgen will also cause the removal of (transitive) reverse dependency: bppsuite. It depends (transitively) on libbpp-core, libbpp-seq, affected by #897780, #897784. You should try to prevent the removal by fixing these RC bugs.