these 4 derivations will be built:
  /nix/store/mihb9zcgmbnjr0dyh769hgf22pbgnfgx-source.drv
  /nix/store/g1sl8l248rsckwrgwwjggbqfajpm91ya-lean-ctx-3.10.2-vendor-staging.drv
  /nix/store/k0jz3zyfjcy41y8gppsp6jfhx2lvs7c7-lean-ctx-3.10.2-vendor.drv
  /nix/store/515pcyylghirxz9ng9cz9sn3zymb1271-lean-ctx-3.10.2.drv