I may be wrong but I am pretty sure that the c_source_file option should point to the actual c file with the implementation rather than the c.h header.
I’m not sure but I also don’t think you need the full translate-c package for this and could use just the built-in addTranslateC methods. I had a question about it a few days ago, it might help you: Error in Zig file Generated from TranslateC
Sorry I couldn’t be more helpful.