HandBrake - asm code fails to build, in the x265 sub-make (and --disable-asm doesn't fix it).
OpenBLAS - ar: strmm_kernel_LN.o: No such file or directory
SU2 - teciosrc/RawArray.h:23:1882: error: no matching function for call to max(const size_t&, long unsigned int)
eduke32 - kgroup fails to link, dunno why yet: undefined reference to `engineDestroyAllocator'
ncbi-blast+ - ncbi-blast-2.11.0+-src/c++/src/corelib/ncbifile.cpp:5182:18: error: narrowing conversion of 2768370933 from unsigned int to int [-Wnarrowing]
nix - multiple issues, broken on both 32-bit and 64-bit, see https://slackware.uk/~urchlay/src/nix.32bit.fail.log and https://slackware.uk/~urchlay/src/nix.64bit.write.to.usr.log
openjdk6 - bedlam is testing now, initial report is 'still broken'...
openjdk7 - FTBFS, it's using gcc-5, but trying to link with /usr/lib/libstdc++.so instead of the one in /usr/lib/gcc/i586-slackware-linux/5.5.0/libstdc++.so
openjdk8 - can't test, needs openjdk8 first.
pixma - install: cannot stat '429/libs_bin/libcnbpcmcm429.so.*': No such file or directory (OK on 64-bit)
sysdig - kernel module ftbfs: __umoddi3 undefined
ugene - src/common/memory_allocator.h:119:23: error: too many arguments to function void* sys_mmap(void*)
virtualbox - can't test (requires virtualbox-kernel)
virtualbox-kernel - ftbfs, does upstream still support 32-bit? (https://www.virtualbox.org/wiki/Linux_Downloads - seems no, 64 bit required? - did this even build on 14.2?)