opencpn fails to cross build from source, because it fails running tests
despite DEB_BUILD_OPTIONS containing nocheck. As host code cannot be
run, there is no expectation of tests succeeding, but we actively need
to skip them to support cross builds. Please find a patch attached that
implements this. I've verified that a native nocheck build exactly
reproduces a full build (i.e. it does not break reproducibility).

Helmut