Gregory's ServerWell, at best I have seen #guix at about 86% #reproducible ...
Today, it is about 92% unknown... the two build farms have a fair amount of catching up to do after the core-updates merge.
"guix" itself is not particularly reproducible, due to non-determinism with parallelism in guile. Parallelism in the Debian package of guix is disabled so is reproducible there, at least!
Would be good to see how much of the #bootstrap is bit-for-bit reproducible!