this derivation will be built:
  /nix/store/s7fmm37zjkm543cg2pd0sb7wvjjs0j27-spec-nixfmt.drv
this path will be fetched (0.4 KiB download, 0.7 KiB unpacked):
  /nix/store/f331d1g7mpdxckwswvg8qr7fxmnsv06i-writable-tmpdir-as-home-hook