Package: racon Version: 1.5.0-2 Severity: serious racon build-depends on libthread-pool-dev which is no longer available on 32-bit architectures, this means that the package can no longer be built on those architectures but the binaries are still in testing/unstable.
In general there are three possible avenues for fixing these kinds of issues, in roughly descending order of preference. 1. Fix libthread-pool-dev to build on 32-bit architectures. 2. Eliminate the build-dependency (either generally or on those architectures) 3. Declare your package unsupportable on 32-bit architectures and file a removal request with the ftpmasters. Which of these are possible in the case of your specific package I do not know.