these 2 derivations will be built:
  /nix/store/fz9nww3ick4zmn0mfs0hr29yd3liahlg-cargo-vendor-dir.drv
  /nix/store/xn0yb37rg7pw8b1f80qjv2vp1xh8f22a-ssync-0.20.0.drv