Package: ftp.debian.org libundead failed to build on armhf after the ldc transition ( https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=908670 ) . This build failure was triggered by a fix for a miscompilation bug and based on what upstream has said I believe that the existing libundead binary was almost-certainly mis-compiled.
As far as I can tell libundead only has two reverse dependencies in Debian, libbiod and sambamba. Neither of these has ever successfully built on armhf. The former has been tried but previously failed with a testsuite failure (possibly due to the aforementioned mis compilation) and now fails with the same error as libundead. The latter has never been tried because it depends on the former. The best long term fix for the underlying issue would be in llvm but they have not yet responded to the bug report (and given the nature of the issue I could see them considering it as a feature request rather than a bug per-se). So for the time being I believe (and Andreas Tille, the effective maintainer agreed) the sensible thing to do is to remove the armhf binaries for libundead.
