anchor.diff:  { name, profile ? ""
   , pkgs ? null, targetPkgs ? pkgs: [], multiPkgs ? pkgs: []
   , extraBuildCommands ? "", extraBuildCommandsMulti ? ""
  +, extraOutputsToInstall ? []
   }:
   
   # HOWTO:
  
positive.code:   staticUsrProfileTarget = nixpkgs.buildEnv {
      name = "${name}-usr-target";
      paths = [ etcPkg ] ++ basePkgs ++ targetPaths;
      ignoreCollisions = true;
    };
  
    staticUsrProfileMulti = nixpkgs.buildEnv {
      name = "system-profile-multi";
      paths = multiPaths;
      ignoreCollisions = true;
    };
  
  
negative.code:     cp -rsHf ${staticUsrProfileTarget}/lib64/* lib64/ && chmod u+w -R lib64/
  
      # copy gcc libs
      cp -rsHf ${chosenGcc.cc.lib}/lib/*   lib32/
      cp -rsHf ${chosenGcc.cc.lib}/lib64/* lib64/
  
      # symlink 32-bit ld-linux.so
      ln -s ${staticUsrProfileTarget}/lib/32/ld-linux.so.2 lib/
  