#
# https://nixos.org/manual/nix/stable/#sec-conf-file
#

# Unix group containing the Nix build user accounts
build-users-group = nixbld

# Enable `nix` CLI (vs legacy nix-* commands) and flakes.
experimental-features = nix-command flakes

# Wheel users may configure extra substituters / import paths without
# the daemon prompting. Safe on a single-user laptop.
trusted-users = root @wheel

# Use every core for every build. Defaults are 1/1, which leaves most of
# the machine idle during big closures (LLVM, protobuf, …).
max-jobs = auto
cores = 0

# Keep build outputs and derivations alive even when only referenced
# from GC roots like direnv envs. Without these, `nix store gc` would
# drop dev-shell deps and force a re-download next `cd` into a project.
keep-outputs = true
keep-derivations = true

# Lift the default 64 MiB download buffer; reduces stalls on big closures.
download-buffer-size = 524288000

# Community-built binary cache. Big hit-rate boost for nixos-unstable
# packages (which is what the registry pin below points at) and for
# anything pulled from nixpkgs that already has community CI coverage.
extra-substituters = https://nix-community.cachix.org
extra-trusted-public-keys = nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=