these 3 derivations will be built:
  /nix/store/7zv6ic9xpzbjmf2csvsi292hdpckh8zr-rand-0.10.2.drv
  /nix/store/w31vnfvk4fjg6q0fskwc432mbzb9p64r-cargo-vendor-dir.drv
  /nix/store/5dliva93f6pb83ccy1vvnbjf3qfl6wkm-fast-nix-gc-proptest-0.1.0.drv
these 3 paths will be fetched (117.1 KiB download, 488.5 KiB unpacked):
  /nix/store/9h20pqvcz8zgfi6plaa83yxjlwh4cbz2-chacha20-0.10.0
  /nix/store/9zqrhd1plrw3cdnn1bkyn4agpa0rakm4-log-0.4.33
  /nix/store/lj0cg2hgh6wf5l89x1rfjfw674f8m0a0-rand_core-0.10.1