Bug#853285: closed by Clint Adams <clint at debian.org> (Bug#853285: fixed in ghc 8.0.2-3)

[Helmut Grohne]

On Tue, Aug 29, 2017 at 10:44:51PM +0100, James Clarke wrote:
> I believe is this because haskell-devscripts-minimal is arch:all, so any
> architecture information does not propagate through. If my understanding is
> correct, making haskell-devscripts-minimal an arch:any package and using a
> :native Build-Depends on haskell-devscripts-minimal would fix this, but I'm
> sure Helmut can clarify?

All of that is correct. Still I don't see that as a good solution for
several reasons:

 * After doing so, every package that uses haskell-devscripts-minimal
   (or haskell-devscripts) will have to annotate its build dependency
   with :native. There are lots of reverse dependencies. I am still
   hoping for a way that causes less churn in the archive.

 * The obvious alternative is to just mark it Multi-Arch: foreign. This
   is not a new idea indeed #769377. Unfortunately it is wrong, because
   the tools in there are architecture-dependent (via exposing ghc
   stuff). From what I learned with pkg-config, cmake and others, I
   guess we'll mark it M-A:foreign anyway and document how to avoid
   issues with architecture-awareness, but this certainly needs more
   work.

 * We'll likely need ghc-for-build and ghc-for-host for a proper
   solution. Since ghc depends on gcc, we also need gcc-for-build and
   gcc-for-host. The latter was blocked by waiting for
   binutils-for-build and binutils-for-host until very recently. Making
   that work for gcc will be a little more work. Any volunteers? ;)

Helmut