anchor.diff:    splashutils_15 = linux;
     sqlite = allBut "i686-cygwin";
     ssmtp = linux;
  +  stdenv = prio 175 all;
     strace = linux;
     su = linux;
     subversion = all;
  
positive.code:   allPackages = import ./all-packages.nix;
  
    pkgs = allPackages {};
  
    /* Perform a job on the given set of platforms.  The function `f' is
       called by Hydra for each platform, and should return some job
  
negative.code: 
    /* Map an attribute of the form `foo = [platforms...]'  to `testOn
       [platforms...] (pkgs: pkgs.foo)'. */
    mapTestOn = pkgs.lib.mapAttrsRecursiveCond
      (as: !(as ? type && as.type == "job"))
      (path: value:
        let
          job = toJob value;
          getPkg = pkgs:
            pkgs.lib.addMetaAttrs { schedulingPriority = toString job.schedulingPriority; }
            (pkgs.lib.getAttrFromPath path pkgs);
        in testOn job.systems getPkg);
  
    /* Common platform groups on which to test packages. */
    linux = ["i686-linux" "x86_64-linux"];
  