Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
If you want minidla to accept connections from the rest of the world, please
add
networking.firewall.allowedTCPPorts = [ 8200 ];
networking.firewall.allowedUDPPorts = [ 1900 ];
to /etc/nixos/configuration.nix.
See <http://lists.science.uu.nl/pipermail/nix-dev/2013-November/011997.html>
for the discussion that lead to this.