[Someone]

I don’t think “one artifact, one vote” is a fair way to measure this.

One reason builds become irreproducible is when a build is multi-threaded, and the order in which artifacts are combined into larger ones becomes unpredictable. That problem doesn’t exist, or at least is a lot smaller, for ‘leaf’ artifacts (example: if your C compiler is single-threaded, and you run make multi-threaded, individual object files do not have the ordering problem, but libraries built from multiple object files do)

On the other hand, a single static struct with a padding “hole” that isn’t consistently written that happens to end up in lots of binaries will decrease your percentage a lot.

[ymse]

Sorry, I think my use of "artifact" here caused some confusion.

Each of these "artifacts" are actual isolated builds of complicated programs such as Chromium or GCC. The technical term is "derivation", which produce "outputs".

All of those packages can be reproduced from source now or 100 years into the future and SHOULD produce the exact same binary output. If they don't, it's a bug.