Unsattisfied dependency python-cffi-backend-api-min (<= 9729)

[Anton Gladky <gladk@debian.org>]

Dear release team,

I am not sure, whether I ask the question, using
the correct address. If I am not right, please redirect
me.

Two of my packages (liggghts and yade) are waiting to
be build on build servers due to unsatisfied dependency
with the following note:

=========
liggghts build-depends on:
- amd64:libvtk6-dev
amd64:libvtk6-dev depends on:
- amd64:python-vtk6 (= 6.3.0+dfsg1-1)
amd64:python-vtk6 depends on:
- amd64:python-twisted
amd64:python-twisted depends on:
- amd64:python-twisted-core (>= 16.2.0-1)
amd64:python-twisted-core depends on:
- amd64:python-openssl
amd64:python-openssl depends on:
- amd64:python-cryptography (>= 1.3)
amd64:python-cryptography depends on missing:
- amd64:python-cffi-backend-api-min (<= 9729)

=========

Can it happen due to some ongoing transitions and I should
just wait?

Thank you

Anton