Merge pull request #3532 from domenkozar/darwin-install-idempotent

darwin installer: remove the file before installing new one

scripts/install-darwin-multi-user.sh

@@ -100,7 +100,7 @@ poly_extra_try_me_commands() {
 poly_configure_nix_daemon_service() {
     task "Setting up the nix-daemon LaunchDaemon"
     _sudo "to set up the nix-daemon as a LaunchDaemon" \
-          /bin/cp -f "/nix/var/nix/profiles/default$NIX_DAEMON_DEST" "$NIX_DAEMON_DEST"
+          /usr/bin/install -m -rw-r--r-- "/nix/var/nix/profiles/default$NIX_DAEMON_DEST" "$NIX_DAEMON_DEST"
 
     _sudo "to load the LaunchDaemon plist for nix-daemon" \
           launchctl load /Library/LaunchDaemons/org.nixos.nix-daemon.plist