On Sun, Dec 03, 2023 at 05:32:38PM +0000, Alastair McKinstry wrote: > Hi,
Hi Alastair, >... > How do I do such a transition? I can't easily test as I lack 32-bit > hardware. It _should_ be fine as MPICH builds and works >... Every amd64 hardware is also i386 hardware, debootstrap --arch=i386 sid i386-chroot chroot i386-chroot is all that it takes for getting into a i386 Debian filesystem on amd64 (but higher level tooling or virtualization might be more convenient). Two issues regarding this transition: 1. Two years ago I did the opposite transition on m68k+sh4, mostly for consistency with the other architectures. These are nocheck architectures, so no information about runtime differences is available. Switching to OpenMPI made SUNDIALS build, which in turn made Octave build. This transition will likely require either making SUNDIALS build without OpenMPI on 32bit, or disabling SUNDIALS support in Octave on 32bit. 2. Packages building for both mpi implementations The 9 yellow packages in the tracker (e.g. ScaLAPACK) currently provide packages for both OpenMPI and MPICH. The easiest solution would be to provide such packages only for the default mpi. Hardcoding architecture lists might work. The more sophisticated solution would be some debian/rules trickery to skip building the OpenMPI variants on 32bit, and for build dependencies creating an empty dependency package libopenmpi-dev-if-available that installs libopenmpi-dev on 64bit and does nothing on 32bit. > Alastair cu Adrian