How can anyone be this interested in maintaining an annex k implementation when it's widely regarded as a design failure, specially the global constraint handler. There's a reason why most C toolchains don't support it.
FWIW, it's heavily used inside Microsoft and is actually pretty nice when combined with all the static analysis tools that are mandatory parts of the dev cycle.
It's only regarded as design failure by the linux folks. Maybe because it came from Microsoft, NIH syndrome.
A global constraint handler is still by far better than dynamic env handlers, and most of the existing libc/POSIX design failures.
You can disable this global constraint handler btw.