these 3 derivations will be built:
  /nix/store/nkp1xhc2xcmdf6nh2ngyfp0i5my81xxa-lean-ctx-3.10.5-vendor.drv
  /nix/store/skiinqjznlhcxwwa4b5wdbjb5mkn8mpa-lean-ctx-3.10.5.drv
  /nix/store/6z1kws9z1zxkngjkfmc9wg7xrryi4957-check-lean-ctx.drv