Comment 3 for bug 1081500

Summary from discussion. There are two general approaches how to structure this:

 (1) A package has one "build myself" test; this is more or less a "Restrictions: needs-build" in debian/tests/control and debian/tests/build being "#!/bin/true". The rebuild test group would then be expressed in terms of mutual build/binary/test dependencies.

 (2) A package has debian/tests/build-* tests for all packages in the group except of its own.

(1) is structurally simpler and scales better, but will always waste the "build myself" part, which is not a triviality in case of gcc or linux. But it is a cleaner design and will ensure that the package still builds regardless of which of its build deps changes.

(2) avoids the wasted "self" builds from above, but will trigger the "other" builds several times unnecessarily if you upload two packages in a group at the same time.

My gut feeling is that we should do (1).