https://tracker.debian.org/pkg/octave-iso2mesh

Issues preventing migration:
∙ ∙ iso2mesh-tools/s390x has unsatisfiable dependency


In 1.9.8+ds-4 iso2mesh-tools gained dependencies on
  octave, octave-jnifti, octave-jsonlab, octave-zmat
and none of the latter 3 is installable on s390x due
to non-availability of octave-zmat.

If it is correct for iso2mesh-tools to have these octave
dependencies, then they have to also become build dependencies
to prevent building on s390x.