If the 'unused variable'-handling is the only thing that holds you back: it's quite simple to build the zig compiler and patch it. See this post by ryuukk in the corresponding issue on github: https://github.com/ziglang/zig/issues/335#issuecomment-10138... and also https://github.com/ziglang/zig/issues/335#issuecomment-10184...

I use this method to build a zig compiler to work with, and when I build a release build of my zig-project I switch to the official compiler and fix the handful 'unused variable' errors. Works fine for me.