Aha, looks like we did add -mword-relocations to LDFLAGS in C_API/buildsupport/common.mk in v2.0, so hopefully that's the magic trick here. I don't think -fPIC is needed, or even wanted since we don't handle global offset tables in the compiler.
Ah thank you very much!! It looks like Zig may not support this flag out of the box, so I may have to add support for it. Will let you know how it goes
Looks like -fPIC on the latest version of Zig gets everything to work now!
Thanks so much again @dave !