anchor.diff:  
     fluentd = {
       src = fetchFromGitHub {
  +      name = "fluentd";
         owner = "fluent";
         repo = "nginx-fluentd-module";
         rev = "8af234043059c857be27879bc547c141eafd5c13";
  
positive.code: 
    coolkit = {
      src = fetchFromGitHub {
        owner  = "FRiCKLE";
        repo   = "ngx_coolkit";
        rev    = "0.2";
  
negative.code:   opentracing = {
      src =
        let src' = fetchFromGitHub {
          name = "opentracing";
          owner = "opentracing-contrib";
          repo = "nginx-opentracing";
          rev = "v0.9.0";
  