Incremental debug builds will of course not be reproducible. Release builds will be.
Re:Zig's New Relationship with LLVM
by kristoff_it on Monday September 28, 2020 @08:53AM
(#24616080)
Quick bootstrapping is one of the goals for 1.0. Related issue: https://github.com/ziglang/zig/issues/6378
[1] https://reproducible-builds.org/
[2] https://bootstrappable.org/