Bug#905346: sbuild should work around missing cross compilation dependencies
During the DebConf18 cross bof it was mentioned that cross building with
sbuild is still difficult, because you need to remember so many options.
One of those options is --add-depends="libc-dev, libstdc++-dev". This
option is necessary, because these dependencies are presently missing
from the relevant crossbuild-essential-$arch packages. Adding them there
would trip them up in britney and prevent testing migration. The problem
is reported as #815172. It has persisted for quite a while now and a
solution will take time (likely it will not be fixed in buster).
pbuilder already works around this limitation. I propose that sbuild
does the same and adds these dependencies to the default that now