these 3 derivations will be built:
  /nix/store/897cvv9vpqgasbdhx4gzplmgw0h3fj64-lean-ctx-3.9.14-vendor-staging.drv
  /nix/store/0mq6y9ggpy05lxp0ncifp1w2fk2b0nsw-lean-ctx-3.9.14-vendor.drv
  /nix/store/x2hq6916hngw62ib9lnf4shgk7q12jcf-lean-ctx-3.9.14.drv