The linked issue suggest that JSONAny Perl package should also be part of the build inputs.

Yes, the old version was failing to update cloudflare without JSONAny. So I added build input as suggested in the linked issue, but then I got an error regarding usage of an old API. After upgrade, I tried to remove JSONAny and it worked without any issues. Here is the exact packageOverride I have in my configuration:

      nixpkgs.config.packageOverrides = super: let self = super.pkgs; in {
        ddclient = super.ddclient.overrideAttrs (
          oldAttrs: rec {
            name = "ddclient-${version}";
            version = "3.9.0";
            src = super.fetchurl {
              url = "mirror://sourceforge/ddclient/${name}.tar.gz";
              sha256 = "0fwyhab8yga2yi1kdfkbqxa83wxhwpagmj1w1mwkg2iffh1fjjlw";
            };
            patches = [];
            buildInputs = oldAttrs.buildInputs ++ (with super.perlPackages; [ DataValidateIP ]);
          }
        );
      };

@c0bw3b according to ddclient changelog, they've switched from JSON::Any to JSON:PP in the new release. This explains why it works without having JSONAny package in buildInputs.

Ah! Nice catch. I guess we should add JSONPP to the inputs list of Perl packages then?

For some reason, cloudflare updates work for me without this dependency, but since it's clearly listed in README file, I added it to build inputs as well.

@GrahamcOfBorg build ddclient

Would this be a candidate for a backport to 18.09?

@benpye I'm not sure really, but maybe @c0bw3b knows more about procedures for backporting.