I have a large tarball which I configure and compile, and then break up
into a number of Debian packages (similar to boost). Unfortunately, one
of the components doesn't compile on 32-bit architectures, which means
that the entire tarball build fails on 32-bit archs. Now, like I said,
`debian/control` lists a number of packages, complete with
```
Package: libmyproject-subpackage-7
Architecture: any
Section: libs
[...]
```
Restricting the architecture to
```
Package: libmyproject-badsubpackage-7
Architecture: amd64
```
only for that one subpackage doesn't cut it.