Bug#972068: arpack: provide 64-bit (ILP64) build

[Drew Parsons]

Source: arpack
Version: 3.7.0-3
Severity: wishlist
Control: affects -1 src:slepc

We have started providing 64-bit (ILP64) variants of our numerical
libraries, which enables computation of vastly larger, more complex
systems.

The blas libraries provide ILP64 builds as libblas64-dev, etc.

mumps and petsc,slepc provide libmumps64-dev, petsc64-dev,
slepc64-dev. But these builds enable 64-bit indexing of matrices, not
full ILP64. For full 64-bit support they will require 64-bit support
in lower level libraries (openmpi, arpack, etc).

ARPACK support is currently removed from the slepc 64-bit build (new
version 3.14) since current ARPACK cannot be used with 64-bit integers.

I'm filing this Bug to request a 64-bit variant of arpack be built.

This would be an extra set of packages (e.g. libarpack2-64-dev,
libarpack2-64) providing libarpack64.so (or libarpack-64.so) alongside
libarpack.so (i.e. coinstallable).  It would be built against
libblas64-dev instead of libblas-dev.

slepc64-dev would then be able to reinstate ARPACK support in the
64-bit build (once the full numerical library stack is ILP64-enabled).


-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.8.0-2-amd64 (SMP w/8 CPU threads)
Kernel taint flags: TAINT_WARN
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE=en_AU:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled