Version 1.4.1-1 of libnbd is marked for autoremoval from testing on Sat 28 Nov 2020. It depends (transitively) on libguestfs, affected by #972241. You should try to prevent the removal by fixing these RC bugs.
about this package. You should make the package lintian clean getting rid of them.
Last update: 2020-08-22
This package is part of the ongoing testing transition known as ocaml-4.11.1.
Please avoid uploads unrelated to this transition, they would
likely delay it and require supplementary work from the release
managers. On the other hand, if your package has problems
preventing it to migrate to testing, please fix them
as soon as possible.
You can probably find supplementary information in the
archives or in the corresponding