Some crates.io hashes cannot be found in Cargo.lock

[YPares]

I'm running into this:

Running phase: unpackPhase
@nix { "action": "setPhase", "phase": "unpackPhase" }
unpacking source archive /nix/store/qc74kg08frlgdjb5fjmwgvb0snpf45lx-unarchiver
source root is unarchiver
Running phase: buildPhase
@nix { "action": "setPhase", "phase": "buildPhase" }
++ crate2nix generate -f ./Cargo.toml -o Cargo-generated.nix -h /nix/store/2mwh4sn153gar2r2ay6x43l7752pr3v3-rustnix-crate2nix/crate-hashes.json
Did not find all crates.io hashes in Cargo.lock. Hashes for e.g. addr2line 0.24.2, adler 1.0.2, adler2 2.0.0, aho-corasick 1.1.3, android-tzdata 0.1.1, android_system_properties 0.1.5, async-channel 2.3.1, async-stream 0.3.6, async-stream-impl 0.3.6, async-trait 0.1.83 are missing.
This is probably a bug.
Prefetching    1/379: https://static.crates.io/crates/encoding_rs/encoding_rs-0.8.35.crate
Error: while prefetching crates for calculating sha256: While spawning 'nix-prefetch-url https://static.crates.io/crates/encoding_rs/encoding_rs-0.8.35.crate --name encoding_rs-0.8.35': No such file or directory (os error 2)
crate2nix failed.

It's difficult to make a minimal reproduction but just in case is it a known error? I tried running cargo update but that doesn't change anything.

[danieldk]

You are bumping into this issue because, most likely, you have git dependency in Cargo.toml. crate2nix will try to determine the crate's hash by downloading the crate using nix-prefetch-git. However, nix-prefetch-git is not added as a dependency to the generatedCargoNix derivation. However, adding it is not going to help you much, since crate2nix runs in a sandbox, so it cannot fetch the crate over the network anyway.

The solution is to run crate2nix in your Rust source folder once. This will create a crate-hashes.json file that contains the fixed-output derivation hashes for the Rust crates that are fetched using git. Add this file to your Nix repo/flake and crate2nix will use it (and not attempt to call nix-prefetch-git).

[YPares]

@danieldk Thanks! I'll try that. I suppose then that I should re-run crate2nix manually everytime a git-provided crate has to change?
I'm not sure it's part of crate2nix documentation, could it be added? I think notably here: https://nix-community.github.io/crate2nix/00_guides/31_auto_generating/

[hallettj]

Hi! I found that this error can occur if you have a dependency that uses the v1 Cargo.toml manifest format. That format has a [metadata] section at the end of the file with dependency checksums instead of putting checksum fields inline with each dependency entry. There is a fix in #381. If you're still seeing this issue you might try running crate2nix from that PR branch to see if it helps.

I agree that git dependencies can also cause this type of error. But looking at the dependency names in the error message you can see all of the names begin with "a". The error output shows the first 10 dependencies with missing checksums in alphabetical order. When you encounter a lock file where crate2nix couldn't find checksums for any dependency you see a lot of "a" names in the error message like in this case. That makes me think this is a v1 manifest problem.