these 5 derivations will be built:
  /nix/store/j09bizyl59kz46vynv31fad44y782y1y-source.drv
  /nix/store/ypxh4dld2gw45hi249kz4f4j9xy5yhhw-lean-ctx-3.12.1-vendor-staging.drv
  /nix/store/baz7v1iik1fmrhfwf4yl7d6z7qqy5044-lean-ctx-3.12.1-vendor.drv
  /nix/store/jlx8qxv1dsynby6z5f5y6pvvnvsj6p9v-lean-ctx-3.12.1.drv
  /nix/store/1a4xllilvxgv3d7bwqczld9zcwv49iji-check-lean-ctx.drv