[Nix-dev] nix-channel can't process channel data from Hydra

[Peter Simons]

Hi,

I use the channel from my own Hydra instance on several machines just fine,
but on one of them I get this error during "nix-channel --update" for no
apparent reason:

  downloading Nix expressions from `http://hydra.cryp.to:8080/jobset/nixpkgs/haskell-updates/channel/latest/nixexprs.tar.bz2'...
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100 32672    0 32672    0     0  22659      0 --:--:--  0:00:01 --:--:-- 22673
  unpacking channels...
  bzip2: (stdin) is not a bzip2 file.
  /nix/store/cv12p8zpy0fp6spirw9ph78byz55r6n0-gnutar-1.26/bin/tar: This does not look like a tar archive
  /nix/store/cv12p8zpy0fp6spirw9ph78byz55r6n0-gnutar-1.26/bin/tar: Exiting with failure status due to previous errors
  builder for `/nix/store/n4hi4l4r5z7z5m20v9v5spwfb9xg728h-hydra-crypto.drv' failed with exit code 2
  error: build of `/nix/store/n4hi4l4r5z7z5m20v9v5spwfb9xg728h-hydra-crypto.drv' failed
  cannot unpack the channels at /run/current-system/sw/bin/nix-channel line 145.

I downloaded the file from that URL manually, and it looks like a perfect
tar-bz2-file to me, so I'm not sure what nix-channel is complaining about,
really.

Does anyone have a suggestion how to debug this issue? Has anyone seen
something like that before?

Take care,
Peter