This didn't fix the compilation errors for me. I can set my own no_mangle pub extern `_Unwind_Resume` function (without declaring it a lang_item) and fix the undefined reference that way, but I'm pretty sure that's not how one's supposed to solve this
Hm, it compiled for me. Well, it didn't know about the C functions that were being linked in, but it didn't complain about the lang items.