Download calculation with omitted FileSize is wrong #606

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opened 2024-12-26 13:43:09 +00:00 by flokli · 1 comment

flokli commented

2024-12-26 13:43:09 +00:00

Describe the bug

I'm using a binary cache that doesn't expose FileSize / FileHash fields.

While being totally a valid NARInfo file, Nix gets its download estimates wrong:

these 3 derivations will be built:
  /nix/store/m6dkr67hk87lpcz9wv8f2mp2zrgsyfp9-nix-2.24.11.drv
  /nix/store/zcfi6vs0z18309asw8fpa9v3665av44v-niv-0.2.22.drv
  /nix/store/g4kvzrs1kk9i13vaa8q1r0y4hgsqsnlp-dev-env.drv
these 112 paths will be fetched (0.00 MiB download, 2649.76 MiB unpacked):
  /nix/store/3qzlg8h5qc1slypy99aafdcgkzj6974h-OneTuple-0.4.2
  /nix/store/pp4540rig52fnj66kz1kiaj1000ja9v0-QuickCheck-2.14.3
  /nix/store/416aqss6p59w6v92127hkz04v0bclx21-StateVar-1.2.2
  /nix/store/b5f93spm2cl9g6x73dnx7ns5irs739fz-aeson-2.1.2.1
  /nix/store/nqnx6k6y103rargdz2gai2rmi389zn6n-aeson-pretty-0.8.10
  /nix/store/11wc4s6a6qi98lxikacw746slhmj5dl7-ansi-terminal-1.0.2
  /nix/store/yy7j66av9lwh3lvbxp1zv7572wb4l7dj-ansi-terminal-types-0.11.5
  /nix/store/cn6m459cbacdwkvjllgy5hkzf045yc1g-appar-0.1.8
  […]

As can be seen, it assumes 0.00 MiB download size and 2649.76 MiB unpacked size.

I assume other CLI frontends with other progress reports are also borked.

Expected Behaviour

If the FileSize field is omitted, it should probably just fall back to use the NARSize field for size calculation, or only report the unpacked size.

Steps To Reproduce

Configure https://nixos.tvix.store as a binary cache
Substitute something
See error

`nix --version` output

nix (Lix, like Nix) 2.91.1

## Describe the bug I'm using a binary cache that doesn't expose FileSize / FileHash fields. While being totally a valid NARInfo file, Nix gets its download estimates wrong: ``` these 3 derivations will be built: /nix/store/m6dkr67hk87lpcz9wv8f2mp2zrgsyfp9-nix-2.24.11.drv /nix/store/zcfi6vs0z18309asw8fpa9v3665av44v-niv-0.2.22.drv /nix/store/g4kvzrs1kk9i13vaa8q1r0y4hgsqsnlp-dev-env.drv these 112 paths will be fetched (0.00 MiB download, 2649.76 MiB unpacked): /nix/store/3qzlg8h5qc1slypy99aafdcgkzj6974h-OneTuple-0.4.2 /nix/store/pp4540rig52fnj66kz1kiaj1000ja9v0-QuickCheck-2.14.3 /nix/store/416aqss6p59w6v92127hkz04v0bclx21-StateVar-1.2.2 /nix/store/b5f93spm2cl9g6x73dnx7ns5irs739fz-aeson-2.1.2.1 /nix/store/nqnx6k6y103rargdz2gai2rmi389zn6n-aeson-pretty-0.8.10 /nix/store/11wc4s6a6qi98lxikacw746slhmj5dl7-ansi-terminal-1.0.2 /nix/store/yy7j66av9lwh3lvbxp1zv7572wb4l7dj-ansi-terminal-types-0.11.5 /nix/store/cn6m459cbacdwkvjllgy5hkzf045yc1g-appar-0.1.8 […] ``` As can be seen, it assumes 0.00 MiB download size and 2649.76 MiB unpacked size. I assume other CLI frontends with other progress reports are also borked. ## Expected Behaviour If the `FileSize` field is omitted, it should probably just fall back to use the NARSize field for size calculation, or only report the unpacked size. ## Steps To Reproduce 1. Configure `https://nixos.tvix.store` as a binary cache 2. Substitute something 3. See error ## `nix --version` output nix (Lix, like Nix) 2.91.1

flokli added the

bug

label

2024-12-26 13:43:09 +00:00

flokli commented

2024-12-26 13:56:02 +00:00

Author

For now I think this can be worked-around on the server side by setting FileSize to NarSize, but the field is optional, so it should probably still be supported.