Arch:all package depending on package that isn't Arch:any

[Kevin Glynn <kevin.glynn@gmail.com>]

This is in reference to serious bug#511184.

The mozart package can only be built for 32 bit architectures, so its
arch line is:

  Architecture: hppa i386 m68k mipsel mips powerpc sparc s390 arm armeb
  armel kfreebsd-i386

Its standard library (package mozart-stdlib) contains only
architecture independent files, and its control file has:

  Package: mozart-stdlib
  Architecture: all
  Depends: mozart (>= 1.3.0)


As bug 511184 points out mozart-stdlib is arch: all but uninstallable
on (e.g.) amd64.

I can't find clear guidance from the developer's reference or policy
(apologies if I've overlooked this).  I see three options:

1. Leave as is (its been like this for years and years).  

   Not installing on amd64 is reasonable.

2. Change the Depends to a Recommends. But policy says:

   The Depends field should be used if the depended-on package is
   required for the depending package to provide a significant amount
   of functionality.  

3. Change mozart-stdlib arch line to list the same architectures as
   mozart. 
 
   yuk.  extra load on the buildds for (very) little benefit.  When
   new architectures get added to Debian (e.g. armel, armeb) I have to
   remember to adjust the mozart-stdlib too.

Any suggestions? anything else? anywhere else I should be asking?
(e.g. maybe on debian-release).

Thanks for your help,

Kevin