anchor.diff:    ];
   
     version = sources.${channel}.version;
  +
  +  libusb' =
  +    if versionAtLeast channel "2.1" then
  +      libusb
  +    else
  +      libusb-compat;
  +
  +  pth' =
  +    if versionAtLeast channel "2.1" then
  +      npth
  +    else
  +      pth;
   in
   
   stdenv.mkDerivation rec {
  
positive.code: let
    inherit (stdenv)
      targetSystem;
    inherit (stdenv.lib)
      elem
      optional
      platforms;
  in
  
  let
    sources = import ./sources.nix;
  
    tarballUrls = version: [
  
negative.code: 
  #, adns
  , bzip2
  , curl
  , gnutls
  , libassuan
  , libgcrypt
  , libgpg-error
  , libksba
  , libusb
  , libusb-compat
  , npth
  , pth
  , openldap
  , pcsclite
  , readline
  