anchor.diff:  
     l_set_games = buildEnv {
       name = "l-set-games";
  +    ignoreCollisions = true;
       paths = [
         higan
         sdlmame
  
positive.code: 
    l_set_media = buildEnv {
      name = "l-set-media";
      paths = [
        l_set_web
        l_set_av
  
negative.code: 
    l_set_av = buildEnv {
      name = "l-set-av";
      ignoreCollisions = true;
      paths = [
        scrot
        geeqie
  