these 2 derivations will be built:
  /nix/store/3zf31qgqpyygkj84740clpqa3k29sgkp-lean-ctx-3.9.13-vendor.drv
  /nix/store/4py5bygcjwk096a5455d3rcd4ax7vhv5-lean-ctx-3.9.13.drv