error: unexpected end-of-file when cache is not found on https://cache.nixos.org

[happysalada]

Describe the bug

When running a nix command sometimes, nix tries to fetch a cache, when the url is 404, the error generated is just
error: unexpected end-of-file

Steps To Reproduce

running

> nix develop -vvv
querying info about '/nix/store/4yy83b75l7v3bcww26l1b05vp54y50k4-nix-shell-env' on 'https://cache.nixos.org'...
downloading 'https://cache.nixos.org/4yy83b75l7v3bcww26l1b05vp54y50k4.narinfo'...
error: unexpected end-of-file

When I try to curl the url, it gives me a 404

I don't know why nix is looking at that path specifically, but I get that error quite often recently.

Here is my flake.lock

{
  "nodes": {
    "nixpkgs": {
      "locked": {
        "lastModified": 1623154001,
        "narHash": "sha256-KxsIXg5ez5SveGayOKcW+MnofqVuLnwZHE5mZgtRAJo=",
        "owner": "nixos",
        "repo": "nixpkgs",
        "rev": "3bc8e5cd23b84b2e149e7aaad57117da16a19e6f",
        "type": "github"
      },
      "original": {
        "owner": "nixos",
        "ref": "nixpkgs-unstable",
        "repo": "nixpkgs",
        "type": "github"
      }
    },
    "root": {
      "inputs": {
        "nixpkgs": "nixpkgs"
      }
    }
  },
  "root": "root",
  "version": 7
}

here is the

❯ nix --version
nix (Nix) 2.4pre20210601_5985b8b

Expected behavior

Is there a way when the cache returns a 404 to try to build the derivation?

I'm not sure what additional information might be needed.

nix-env --version output

❯ nix-env --version
nix-env (Nix) 2.4pre20210601_5985b8b

Additional context

I have those experimental-features enabled

      experimental-features = nix-command flakes ca-derivations ca-references

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/content-addressed-nix-call-for-testers/12881/102

[thufschmitt]

Thanks for reporting. Do you have the full Nix code available so that I can try to reproduce it?

Also, is the Nix daemon using the same Nix version as the client?

(Btw, nix develop is currently broken with CA derivations)

[happysalada]

nix daemon is using the same version yes

❯ nix-daemon --version
nix-daemon (Nix) 2.4pre20210601_5985b8b

Understood that nix-develop is broken with CA derivations.

Unfortunately, I can't reproduce systematically the error. Sometimes it happens with a particular code, and then it doesn't happen anymore.

It happens to be sometimes with my dotfiles
github.com/happysalada/dotfiles
running something like nix build .\#darwinConfigurations.raphael.system but it's not consistent.
(my next move is to disable the ca-* and see if the error persists, to see if it is related).
When there is a problem, I try to forcefully repeat the command many times and it succeeds at some point.
I thought that it was because of the gc running or something, but I've deactivated automatic gc.
I will try another -vvv to see if I can get more information.
I was thinking of looking for what happens when the cache.nixos.org returns a 404, how it is handled.

[bbigras]

I don't know if it could help reproduce it, but on my system I just need to run this:

❯ nix-env --quiet -j8 -iA cachix -f https://cachix.org/api/v1/install
error: unexpected end-of-file

[happysalada]

If you want to check if it is the same error, you can run your command again with the flag -vvv it should give you more information. If there is a 404 in there when requesting a cache, it could be the same!

[bbigras]

❯ nix-env -vvv --quiet -j8 -iA cachix -f https://cachix.org/api/v1/install
downloading 'https://cachix.org/api/v1/install'...
evaluating file '/nix/store/j24029fbiy3nlrcssbq7rdl8ljjym54f-source'
evaluating file '/nix/store/7l15l15d9wmh0fwpr943xqll9bpvq3pi-env-manifest.nix'
installing 'cachix-0.6.1'
error: unexpected end-of-file

[happysalada]

Thank you for the added info!

I have to say it doesn't look like the same error.
From what I gathered from other people, that unexpected end-of-file error could also be due to a problem between the nix-env and the nix-daemon version being different. If that is not the case for you as well, then it may be something else.

[domenkozar]

It can be that nix-daemon crashes, do look at the logs.

[bbigras]

jun 29 16:48:42 desktop nix-daemon[307391]: nix-daemon: src/libstore/derivations.cc:630: static std::string_view nix::BasicDerivation::nameFromPath(const nix::StorePath&): Assertion `hasSuffix(nameWithSuffix, extension)' failed.
jun 29 16:48:44 desktop systemd-coredump[307398]: [🡕] Process 307391 (nix-daemon) of user 0 dumped core.

[bbigras]

Should I open a new issue for the crash? In this repo?

[domenkozar]

@bbigras please :)