anchor.diff:      linux-headers
       openssl_1-0-2
       pam
  -    stdenv.libc
  +    stdenv.cc.libc
     ];
   
     postUnpack = ''
  
positive.code:   '';
  
    NIX_LDFLAGS = [
      "-L${stdenv.libc}/lib -lcrypt"
    ];
  
    makeFlags = [
  
negative.code:     (substituteAll {
        src = ./nix-purity.patch;
        inherit libpcap;
        glibc = stdenv.cc.libc;
      })
      # Gentoo patchset 2.4.7-2
      # https://dev.gentoo.org/~pinkbyte/distfiles/patches/
  