anchor.diff:  
         buildCores = mkOption {
           type = types.int;
  -        default = 1;
  +        default = 0;
           example = 64;
           description = ''
             This option defines the maximum number of concurrent tasks during
  -          one build. It affects, e.g., -j option for make. The default is 1.
  +          one build. It affects, e.g., -j option for make. The default is 0.
             The special value 0 means that the builder should use all
             available CPU cores in the system. Some builds may become
  -          non-deterministic with this option; use with care! Packages will
  -          only be affected if enableParallelBuilding is set for them.
  +          non-deterministic with this option; use with care!
           '';
         };
   
  
positive.code: 
        maxJobs = mkOption {
          type = types.int;
          default = 1;
          example = 64;
          description = ''
            This option defines the maximum number of jobs that Nix will try
            to build in parallel.  The default is 1.  You should generally
            set it to the total number of logical cores in your system (e.g., 16
            for two CPUs with 4 cores each and hyper-threading).
          '';
  
negative.code:         binary-caches = ${toString cfg.binaryCaches}
          trusted-binary-caches = ${toString cfg.trustedBinaryCaches}
          binary-cache-public-keys = ${toString cfg.binaryCachePublicKeys}
          auto-optimise-store = ${toString cfg.autoOptimiseStore}
          ${optionalString cfg.requireSignedBinaryCaches ''
            signed-binary-caches = *
          ''}
  