this derivation will be built:
  /nix/store/4g81a25ppcmhg1iil2ggdw0mwsxmvc80-nix-shell.drv
this path will be fetched (2.3 MiB download, 6.2 MiB unpacked):
  /nix/store/0bijdnipw09bsvggaigv4rcdf2p03iyn-perf-linux-7.3.1