these 2 derivations will be built:
  /nix/store/vxddnxbycy2avxbi1wnxmnx8gjcq2w67-devshell-dir.drv
  /nix/store/gylymgdm3j6fb7cggrwmpnf0ad7mksv1-devshell.drv
this path will be fetched (222.2 MiB download, 634.8 MiB unpacked):
  /nix/store/2x1b3jkwhkg52xa5bnqrc7n04vz23n3b-dart-3.13.0