abiword cannot satisfy its cross Build-Depends, because its dependency
on libenchant-2-dev is not satisfiable. In general, Architecture: all
packages can never satisfy cross Build-Depends unless marked Multi-Arch:
foreign or annotated :native. Since libenchant-2-dev is a transitional
package, it should have the same Architecture and Multi-Arch value as
the target package. Doing so resolves the problem for abiword. I'm
attaching a patch for your convenience.

Helmut