Bug#760936: BLAS: not Multi-Arch safe

[Thorsten Glaser]

Package: libblas3
Version: 1.2.20110419-7
Severity: important

libblas3 Provides: libblas.so.3
libatlas3-base Provides: libblas.so.3

The problem here is that I can install, for example,
libblas3:amd64 and libatlas3-base:i386, and they are
managed by the same alternative.

Helmut and I think you need to move the libblas.so.3
symlink into arch-qualified subdirectories and manage
multiple alternatives, one per architecture.

Helmut suggested to just add "Conflicts: libblas.so.3"
to all providers of the libblas.so.3 virtual package,
so they are not coïnstallable, then drop the alternatives
Geraffel and just use normal M-A coïnstallability. Please
do enlighten us to the reason of this alternatives system ☺

Related is #760821 which is an error (partially) caused
by this problem.

-- System Information:
Debian Release: jessie/sid
  APT prefers unreleased
  APT policy: (500, 'unreleased'), (500, 'buildd-unstable'), (500, 'unstable')
Architecture: x32 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.14-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=C, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/lksh

Versions of packages libblas3 depends on:
ii  libc6         2.19-10
ii  libgcc1       1:4.9.1-12
ii  libgfortran3  4.9.1-12
ii  libquadmath0  4.9.1-12

libblas3 recommends no packages.

libblas3 suggests no packages.

-- no debconf information