packagereason
bluegriffon closed source, doesn't provide a i686 Ubuntu package anymore since version 2.4
bluegriffon-i18n see bluegriffon
ceph fails fatally in check() - see FS32#21
cuda cuda 9.0 is 64-bit only
dmd fails to build, upstream is unresponsive, see forum
dotnet-core not available for 32-bit on linux, see here
fox-devel fails on non 64-bit Intel, blacklisting for now, see FS32#13
linux-hardened not really useful on i686 + hard to maintain
libretro-citra do not build, see FS32#23
libretro-mupen64plus do not build, see FS32#23
libretro-parallel-n64 do not build, see FS32#23
libretro-ppsspp do not build, see FS32#23
luxrays does not compile on i686 - see FS#54960
mongodb dropped support for 32-bit in version 3.4
nsjail kafel has no 32-bit Intel support, see also forum
opera dropped 32-bit version in version 46.0.2597.26
opera-ffmpeg-codecs as opera itself is blacklisted
ospray "Your Embree build needs to support at least one ISA >= SSE4.1!"
ovmf "ERROR: This package must be built under the x86_64 architecture.", UEFI for VMS, of little use anyway with 32-bit machines
parallel-netcdf-openmpi requires MPI_Offset >= 8, which is not (yet?) possible on 32 bits - see https://github.com/open-mpi/ompi/issues/3195
python-pytorch Gloo can only be built on 64-bit systems
qcef contains CEF binaries (not current ones) for 64-bit and MIPS only, no 32-bit Intel. Discuss with the authors if you need it.
reflector supports Archlinux mirrors and not Archlinux32 mirrors (yet)
rubinius Support for non-64bit platforms was deprecated 1 Jun 2016 and has now been removed. If non-64bit support is a critical feature for your application, please email contact@rubinius.com
skia-sharp does not provide a bin/gn for 32-bit Linux, see FS32#8
skia-sharp58 does not provide a bin/gn for 32-bit Linux, see FS32#8
vc "Unsupported target architecture 'i686'. No support_???.cpp file exists for this architecture", complain upstream if you need it
wiredtiger WiredTiger requires a 64-bit build
zcash We don't yet support 32bit systems (and we won't by launch) but we can look into this after launch.