anchor.diff:      export NIX_GCC_NEEDS_GREP=1
     '';
   
  +  prehookNetBSD = builtins.toFile "prehook-netbsd.sh" ''
  +    source ${prehookBase}
  +    
  +    alias make=gmake
  +    alias sed=gsed
  +    export MAKE=gmake
  +    shopt -s expand_aliases
  +    
  +    # Filter out stupid GCC warnings (in gcc-wrapper).
  +    export NIX_GCC_NEEDS_GREP=1
  +  '';
  +
     prehookCygwin = builtins.toFile "prehook-cygwin.sh" ''
       source ${prehookBase}
       
  
positive.code:   shell = "/bin/bash";
  
    path = (if system == "i386-sunos" then [ "/usr/gnu" ] else []) ++
      ["/" "/usr" "/usr/local"];
  
    prehookBase = builtins.toFile "prehook-base.sh" ''
  
negative.code:         if system == "i686-darwin" || system == "powerpc-darwin" then prehookDarwin else
          if system == "i686-freebsd" then prehookFreeBSD else
          if system == "i686-openbsd" then prehookOpenBSD else
  	if system == "i686-netbsd" then prehookNetBSD else
          prehookBase;
  
        initialPath = extraPath ++ path;
  