The affected packages cannot be cross built from source, because their
dependency on python3-absl is not cross-satisfiable. In general,
Arch:all packages can never satisfy cross Build-Depends unless marked
Multi-Arch: foreign or annotated :native. python3-absl is a pure Python
module with no non-stdlib dependencies of its own. Therefore the foreign
marking is applicable here. I'm attaching a patch for your convenience.

Helmut