Re: Binary substituter

[Ludovic Courtès]

Starting from eba783b, the substituter maintains a local cache (by
default under /nix/var/nix/substitute-binary/cache) of lookups of
binaries.

So if you look for a given /nix/store file name several times in a row,
only the first time does it actually connect to hydra.gnu.org to check
if it’s there.

(Nix’s substituter implements the same strategy, though slightly
differently.)

Ludo’.