anchor.diff:  
     subversion = subversion14;
   
  -  subversion14 = import ../applications/version-management/subversion-1.4.x {
  +  subversion14 = makeOverridable (import ../applications/version-management/subversion-1.4.x) {
       inherit fetchurl stdenv apr aprutil expat swig zlib jdk;
       neon = neon026;
       bdbSupport = getConfig ["subversion" "bdbSupport"] true;
  
positive.code:     in
        import (dir + "/${pVersion}.nix") (args // { version = pVersion; });
  
  
    ### STANDARD ENVIRONMENT
  
  
  
negative.code:   # configuration option, which must be a function that takes `pkgs'
    # as an argument and returns a set of new or overriden packages.
    # `__overrides' is a magic attribute that causes the attributes in
    # its value to be added to the surrounding `rec'.  The
    # `packageOverrides' function is called with the *original*
    # (un-overriden) set of packages, allowing packageOverrides
    # attributes to refer to the original attributes (e.g. "foo =
    # ... pkgs.foo ...").
    __overrides = (getConfig ["packageOverrides"] (pkgs: {})) pkgsOrig;
  
    pkgsOrig = pkgsFun {}; # the un-overriden packages, passed to packageOverrides
    pkgsOverriden = pkgsFun __overrides; # the overriden, final packages
    pkgs = pkgsOverriden;
    
  
    # The package compositions.  Yes, this isn't properly indented.
    pkgsFun = __overrides: rec {
  
  
    inherit __overrides;
  