The affected packages fail to cross build from source, because they fail
running a host architecture peg or leg. This usually means that it
should be installed for the build architecture. As peg is a parser
generator its input (grammer) and output (source code) is generally
architecture-independent. That makes it a prime candidate for marking
Multi-Arch: foreign. Doing causes it to be installed for the build
architecture of those cross builds. I'm attaching a patch for your
convenience.

Helmut