No rev specified

[energizah]

I'm getting an error which I don't understand. As far as I can tell, I have specified revisions for all of the dependencies, but it errors with No 'rev', 'tag' or 'branch' specified.

{
    "naersk": {
        "branch": "master",
        "description": "Build rust crates in Nix. No configuration, no code generation, no IFD. Sandbox friendly.",
        "homepage": "",
        "owner": "nmattia",
        "repo": "naersk",
        "rev": "1dd63230066a93c61ab7a66934eb0aae3f1a3613",
        "sha256": "1xn8m62ypg13jh4zf101qmfa6gy8cl923fgwvk9c33m573h3k154",
        "type": "tarball",
        "url": "https://github.com/nmattia/naersk/archive/1dd63230066a93c61ab7a66934eb0aae3f1a3613.tar.gz",
        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
    },
    "niv": {
        "branch": "master",
        "description": "Easy dependency management for Nix projects",
        "homepage": "https://github.com/nmattia/niv",
        "owner": "nmattia",
        "repo": "niv",
        "rev": "f73bf8d584148677b01859677a63191c31911eae",
        "sha256": "0jlmrx633jvqrqlyhlzpvdrnim128gc81q5psz2lpp2af8p8q9qs",
        "type": "tarball",
        "url": "https://github.com/nmattia/niv/archive/f73bf8d584148677b01859677a63191c31911eae.tar.gz",
        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
    },
    "nixpkgs": {
        "branch": "nixos-19.09",
        "description": "A read-only mirror of NixOS/nixpkgs tracking the released channels. Send issues and PRs to",
        "homepage": "https://github.com/NixOS/nixpkgs",
        "owner": "NixOS",
        "repo": "nixpkgs-channels",
        "rev": "e10c65cdb35b6a66491e47e5a85f5d456b4f4eea",
        "sha256": "19csb2s3wyav83zcw9dw488zk2fnz6wcxxz8q6hy43dbph86hxwm",
        "type": "tarball",
        "url": "https://github.com/NixOS/nixpkgs-channels/archive/e10c65cdb35b6a66491e47e5a85f5d456b4f4eea.tar.gz",
        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
    }
}

{pkgs, fetchFromGitHub }:

let
  name = "vector";
  version = "0.9.2";
  sources = import ./nix/sources.nix;
  naersk = pkgs.callPackage sources.naersk { };

in naersk.buildPackage {
  inherit name version;
  src = fetchFromGitHub {
    owner = "timberio";
    repo = "vector";
    rev = "v${version}";
    sha256 = "050x6blm11b90kl2bdlk4v5f43fy5js1fpsykayyx9a3q9vd60cv";
  };
}

$ nix-build -E '(import <nixpkgs> {}).callPackage ./default.nix {}'  --show-trace
error: while evaluating the attribute 'builtDependencies' of the derivation 'vector-0.9.2' at /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/build.nix:133:5:
while evaluating the attribute 'cargoconfig' of the derivation 'vector-deps-0.9.2' at /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/build.nix:133:5:
while evaluating 'toTOML' at /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/builtins/to-toml.nix:119:12, called from /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/build.nix:145:19:
while evaluating 'concatMapStringsSep' at /nix/store/2pdw4wsfdg0mrg9d6kj6myyimimvnj4d-nixos-20.09pre226148.0f5ce2fac0c/nixos/lib/strings.nix:88:5, called from /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/builtins/to-toml.nix:132:7:
while evaluating 'foldl' at /nix/store/2pdw4wsfdg0mrg9d6kj6myyimimvnj4d-nixos-20.09pre226148.0f5ce2fac0c/nixos/lib/lists.nix:80:20, called from /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/builtins/to-toml.nix:122:14:
while evaluating 'foldl'' at /nix/store/2pdw4wsfdg0mrg9d6kj6myyimimvnj4d-nixos-20.09pre226148.0f5ce2fac0c/nixos/lib/lists.nix:82:16, called from /nix/store/2pdw4wsfdg0mrg9d6kj6myyimimvnj4d-nixos-20.09pre226148.0f5ce2fac0c/nixos/lib/lists.nix:86:8:
while evaluating anonymous function at /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/builtins/to-toml.nix:124:16, called from /nix/store/2pdw4wsfdg0mrg9d6kj6myyimimvnj4d-nixos-20.09pre226148.0f5ce2fac0c/nixos/lib/lists.nix:85:14:
while evaluating 'tomlTy' at /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/builtins/to-toml.nix:102:12, called from /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/builtins/to-toml.nix:126:20:
while evaluating the attribute 'v' at /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/builtins/to-toml.nix:130:44:
while evaluating the attribute 'source' at /nix/store/g76zggan9y6g82wais1zmrwx5d41vpvd-source/build.nix:146:7:
No 'rev', 'tag' or 'branch' specified

[evanjs]

So this seems to happen for git dependencies in Cargo.toml that do not specify a rev or etc in my case.
Output of (lib.traceVal e) @ https://github.com/nmattia/naersk/blob/dcee40445cfe301ced2d1b11290d6a94ff3aadb9/build.nix#L158
trace: { checkout = <CODE>; key = <CODE>; name = "spi_ccp"; url = "<private-git-url>"; }

Dependency from Cargo.toml:
spi_ccp = { git = "<private-git-url>", version = "1.0.0" }

I can confirm that adding branch to the above dep, e.g.:
spi_ccp = { git = "<private-git-url>", version = "1.0.0", branch = "master" }
Seems to get me past the error mentioned in the OP

[nmattia]

Sorry for the delay, slowly catching up on notifications after some time out.

Ah, yes, fetchGit won't be happy without a revision! Do you mean that the Cargo.lock does not record one?

[evanjs]

Realizing I might have done a bit too much redacting :P

No rev specified in Cargo.toml

# Cargo.toml
# ...
[dependencies.spi_ccp]
git = "ssh://git@<private-git-server>:7999/comm/spi_ccp.git"
version = "1.0.0"
# ...

# Cargo.lock
# ...
[[package]]
name = "spi_ccp"
version = "1.0.0"
source = "git+ssh://git@<private-git-server>:7999/comm/spi_ccp.git#59f363531f91cb8ea239beab078484a4fc3fc070"
dependencies = [
 "serialport",
]
# ...

Rev specified in Cargo.toml

# Cargo.toml
# ...
[dependencies.spi_ccp]
git = "ssh://git@<private-git-server>:7999/comm/spi_ccp.git"
version = "1.0.0"
rev = "59f363531f91cb8ea239beab078484a4fc3fc070"
# ...

# Cargo.lock
# ...
[[package]]
name = "spi_ccp"
version = "1.0.0"
source = "git+ssh://git@<private-git-server>:7999/comm/spi_ccp.git?rev=59f363531f91cb8ea239beab078484a4fc3fc070#59f363531f91cb8ea239beab078484a4fc3fc070"
dependencies = [
 "serialport",
]
# ...

Note that the contents of Cargo.lock seem to be unchanged... except the rev is specified twice
It is, however, initially given as a parameter (?rev=...) and again after a #
This still seems to get resolved properly, though.

It's almost as if naersk is failing due to not finding certain keys in Cargo.toml, rather than Cargo.lock

[nmattia]

Ok, had a proper look at this!

First of all, I didn't realize it was actually naersk throwing the error: https://github.com/nmattia/naersk/blob/648f8c9ccec2a5e56c701895d6ce952b71f0e884/lib.nix#L91-L92

So if the Cargo.toml does not have a rev (or branch or tag) then it throws the error. It looks like a few lines after that we parse the Cargo.lock for a rev (if there is no revision set in the Cargo.toml). So basically, we could first try to parse the Cargo.lock for a rev, and, if one is found, then we simply don't throw the error. It's a matter of moving a few lines up. Is that something that you think would be useful for you?

[evanjs]

I do think that such a change, in allowing us to rely on the rev inferred by Cargo.lock, would solve this issue and improve the UX of naersk.

Not sure if not providing a rev or etc in Cargo.toml would impact determinism, but I'm assuming this is fine, as that's what Cargo.lock is for.