let matches = optgroups().parse(&["--test".to_string(), "--cfg=test".to_string()]).unwrap();
let (sess, cfg) = mk_session(matches);
let cfg = build_configuration(&sess, to_crate_config(cfg));
let matches = optgroups().parse(&["--test".to_string(), "--cfg=test".to_string()]).unwrap();
let (sess, cfg) = mk_session(matches);
let cfg = build_configuration(&sess, to_crate_config(cfg));