My default nix configuration on NixOS. This configuration is more for building/debugging stuff and caching with nix-serve. Usually my package version is locked since different versions of nix can have some effects. nix { config, ... }: { nix = { package = (import ../versions.nix).nix_2_17 { inherit config; }; settings = { log-lines = 25; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-log-lines fallback = true; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-fallback tarball-ttl = 0; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-tarball-ttl show-trace = true; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-show-trace connect-timeout = 5; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-connect-timeout auto-optimise-store = true; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-auto-optimise-store narinfo-cache-negative-ttl = 0; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-narinfo-cache-negative-ttl narinfo-cache-positive-ttl = 0; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-narinfo-cache-positive-ttl builders-use-substitutes = true; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-builders-use-substitutes min-free = 268435456; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-min-free (256 MB in Bytes) max-free = 1073741824; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-max-free (1 GB in Bytes) allowed-users = [ "root" "@wheel" ]; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-allowed-users trusted-users = [ "root" "@wheel" ]; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-trusted-users experimental-features = "nix-command flakes"; # https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-experimental-features }; }; } My nix-configuration.nix on version 23.05