I have set up an intra-company nix cache on an internal CI server.
It provides dependencies much faster than cache.nixos.org as it is local.
My local nix.conf specifies both the internal CI server as well as cache.nixos.org as substituters.
I’ve noticed that the internal CI server is picked for paths that exist on BOTH caches.
I wondered how does it pick a CI server so I tried changing the order of the CI servers in nix.conf but it kept picking the internal CI server.
Does Nix do some latency/speed check to choose a substituter?