I gave it a shot and tried an amd64 bulk build with LLVM 18.

The good news is that there were only four build failures.  The bad
news is that the cython one prevented the interesting 1/3 of the
tree from any attempt at building.

devel/gconf2            cc: error: unknown argument: '-export_dynamic'
devel/mklittlefs        variable length arrays in C++ are a Clang extension
lang/cython,python3     LLVM ERROR: out of memory
textproc/p5-SWISH-API   Failed to create index file 't/index.swish-e

-- 
Christian "naddy" Weisgerber                          naddy@mips.inka.de