sslh has unsatisfiable cross Build-Depends. The binutils dependency is
natively implied in build-essential. It can be dropped with no
replacement. The other two issues are libio-socket-inet6-perl and lcov,
both of which are only used for testing and thus can be annotated
<!nocheck>, which renders them irrelevant to cross building. I'm
attaching a patch for your convenience.

Helmut