nixpkgs/pkgs/tools/networking/dd-agent

To update v6 (v5 is deprecated and should be removed):

1. Bump version, rev, sha256 and payloadVersion in 6.nix
2. git clone https://github.com/DataDog/datadog-agent.git && cd datadog-agent
3. git checkout <tag>
4. nix-env -i -f https://github.com/nixcloud/dep2nix/archive/master.tar.gz
5. deps2nix
6. cp deps.nix $NIXPKGS/pkgs/tools/networking/dd-agent/deps.nix