[ "$(id -u)" != 0 ] || {
log_status "ERROR: running as root"
exit 1
}

[ "$(nix --version)" = "nix (Nix) $(cat version)" ] || {
log_status "installing Nix core tools"
sh ./install
}
. ~/.nix-profile/etc/profile.d/nix.sh

gcroots="$OLDPWD"/.cache/nix/gcroots
log_status "registering Nix dependencies into $(realpath -m --relative-to="$OLDPWD" $gcroots)/"
rm -rf $gcroots # NOTE: remove dependencies no longer set in shell.nix
mkdir -p $gcroots
nix-instantiate >/dev/null shell.nix \
 --indirect --add-root $gcroots/shell.drv
nix-store >/dev/null ${OFFLINE:+--option substituters ""} \
 --indirect --add-root $gcroots/shell.dep \
 --realise $(nix-store --query --references $gcroots/shell.drv)

use nix    shell.nix --pure
watch_file shell.nix