these 3 derivations will be built:
  /nix/store/gwpg9mxmd8kvh2jk2xdd1cmn637qvgx1-source.drv
  /nix/store/xr9qqwwgkdkjfnrpap2c84zp4x7h93xv-lean-ctx-3.12.2.drv
  /nix/store/xsw28nmbiipcciv5qdvqzzrvnnqxcc13-check-lean-ctx.drv