these 2 derivations will be built:
  /nix/store/89s1n2iqr7mza1pkqjq4iygiq5knk17x-cargo-vendor-dir.drv
  /nix/store/a7p0jrfvx20lmxpx5prbrixpz4x2v3q2-ssync-0.19.3.drv