this derivation will be built:
  /nix/store/223l31qfjj63na92vg7ws5fghdndl27k-nix-shell.drv
this path will be fetched (5.8 MiB download, 18.5 MiB unpacked):
  /nix/store/rl3j1za9dpdri1vr52vl69y1qczjb5zv-rustfmt-1.97.1