error[E0603]: module `context` is private
  --> external/gazelle_rust/rust_parser/lockfile_crates.rs:23:31
   |
23 |     let context: cargo_bazel::context::Context = match serde_json::from_str(&lockfile_str) {
   |                               ^^^^^^^ private module
   |
note: the module `context` is defined here
  --> external/rules_rust/crate_universe/src/lib.rs:6:1

error[E0603]: module `utils` is private
   --> external/gazelle_rust/rust_parser/lockfile_crates.rs:135:43
    |
135 |         package.crate_name = cargo_bazel::utils::sanitize_module_name(&package.name);
    |                                           ^^^^^ private module
    |
note: the module `utils` is defined here
   --> external/rules_rust/crate_universe/src/lib.rs:11:1

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0603`.
Aspect @rules_rust//rust/private:clippy.bzl%rust_clippy_aspect of //:gazelle-rust up-to-date (nothing to build)
INFO: Elapsed time: 1.777s, Critical Path: 0.09s
INFO: 2 processes: 2 internal.

We are wanting to switch to gazelle to generate our rust files for us since we have had great success with go's gazelle. Currently we are seeing these errors while using this version of rules rust in our WORKSPACe file

http_archive(
    name = "rules_rust",
    sha256 = "6357de5982dd32526e02278221bb8d6aa45717ba9bbacf43686b130aa2c72e1e",
    urls = ["https://github.com/bazelbuild/rules_rust/releases/download/0.30.0/rules_rust-v0.30.0.tar.gz"],
)

Here's what I have: zemn-me/monorepo@674bff4

When I run bazel run //:gazelle, I get:

gazelle: /Users/tshadwell/code/monorepo-sl/BUILD.bazel: unknown directive: gazelle:prefix
Could not parse lockfile /Users/tshadwell/code/monorepo-sl/cargo.bazel.lock: expected value at line 1 column 1
gazelle: /Users/tshadwell/code/monorepo-sl/cargo.bazel.lock: failed to parse lockfile crates: invalid size

I'm working on the new monorepo project based on the existing Cargo project, we decided to use Blzmod instead of the old Workspace.
We have applied the hybrid mode but IMO should support Bzlmod by default:

• Use new naming convention: gazelle instead of bazel_gazelle, rules_go instead of io_bazel_rules_go
• Easy to setup

I propose a PR that I have use as local module: #9

I'm having some troubles with a Cargo workspace that uses Cargo.toml files as the source of truth. Gazelle will generate third-party dependencies fine. But, I can't seem to get Gazelle to automatically generate the deps attributes properly for other workspace members.

Let's say I have a some Cargo.tomls like this:

# Cargo.toml
[workspace]
members = ["foo", "bar"]
resolver = "2"

# foo/Cargo.toml
[package]
name = "foo"
version = "0.1.0"
edition = "2021"

[dependencies]
bar = { version = "0.1.0", path = "../bar" }

# bar/Cargo.toml
[package]
name = "bar"
version = "0.1.0"
edition = "2021"

[dependencies]

And I import bar in foo:

// foo/src/lib.rs

use bar::*;

Whenever I run Gazelle, it does not find the dependency for bar:

$ bazel run //:gazelle
<snip>
gazelle: @test_workspace//foo/src:lib: no match for bar

I'm not 100% sure I've got the workspace setup properly. As mentioned, Gazelle can find third-party dependencies alright (I use things like clap and tracing in the actual workspace). But, that might be handled differently from first-party dependencies.

Looking at the examples/tests, nothing seems to use Cargo.toml files as the source of truth with gazelle_rust. Is it that this use case hasn't been fleshed out yet? If not, any thoughts on what the issue could be?

no-panic crate is not recognized

Problem

I have the following Rust file that uses the no-panic crate. However, the gazelle plugin does not recognize the dependency in the following Rust code:

// apps/main.rs

use no_panic::no_panic;

#[no_panic]
fn main() {
    println!("Hello, world!");
}

When I run Gazelle, it does not recognize the no-panic crate:

$ bazel run //:gazelle

INFO: Analyzed target //:gazelle (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
Target //:gazelle up-to-date:
  bazel-bin/gazelle-runner.bash
  bazel-bin/gazelle
INFO: Elapsed time: 0.198s, Critical Path: 0.00s
INFO: 1 process: 1 internal.
INFO: Build completed successfully, 1 total action
INFO: Running command line: bazel-bin/gazelle
gazelle: @workspace//apps:main: no match for no_panic

And here's the resulting BUILD.bazel file.

# apps/BUILD.bazel

load("@rules_rust//rust:defs.bzl", "rust_binary")

rust_binary(
    name = "main",
    srcs = ["main.rs"],
)

Potential causes

• gazelle_rust does not recognize procedural macro crates
• gazelle_rust does not realize - in crate names become _ in Rust code

Debug steps

I tried renaming the crate in the crate in the WORKSPACE file.

"no_panic": crate.spec(
    package = "no-panic",
    version = "0.1.26",
),

Bazel files

Here's the applicable sections of my Bazel configuration to help debug things.

# WORKSPACE

# version info
RULES_RUST_VERSION = "0.28.0"
RUST_EDITION = "2021"
RUST_VERSION = "1.73.0"
GAZELLE_RUST_COMMIT = "92761c83eaa076d01c10ca6215c13094f68c35bc"
GAZELLE_VERSION = "0.33.0"

crates_repository(
    name = "crates",
    cargo_lockfile = "//:Cargo.Bazel.lock",
    lockfile = "//:cargo-bazel-lock.json",
    packages = {
        "no-panic": crate.spec(
            package = "no-panic",
            version = "0.1.26",
        ),
    },
    render_config = render_config(
        default_package_name = "",
    ),
)

# BUILD.bazel

load("@bazel_gazelle//:def.bzl", "DEFAULT_LANGUAGES", "gazelle", "gazelle_binary")

gazelle(
    name = "gazelle",
    gazelle = ":gazelle_bin",
)

gazelle_binary(
    name = "gazelle_bin",
    languages = DEFAULT_LANGUAGES + ["@gazelle_rust//rust_language"],
)

Thank you for your hard work on this project. I'm really excited to use these rules.

I think the current code is a little out of sync with upstream rules_rust:

ERROR: Error computing the main repository mapping: at /private/var/tmp/_bazel_tshadwell/15310e5df52295849af33b570a7d9e6c/external/gazelle_rust/deps2.bzl:7:6: cannot load '@rules_rust//proto:repositories.bzl': no such file

I think the file you're looking for is now in https://github.com/bazelbuild/rules_rust/blob/main/proto/protobuf/repositories.bzl

I heard about this plugin only in the Slack Bazel chat:

Daniel Wagner-Hall
2023-08-25
There is https://github.com/Calsign/gazelle_rust but IIRC it just works from .rs files not Cargo.toml

It is also weirdly ungoogleable for me with "gazelle rust bazel".

It would be awesome if you create a PR to include it here:

https://github.com/bazelbuild/bazel-gazelle#supported-languages

(I am also happy to do it for you)

Hey, really like the project and would like to contribute if you are open to it. With that in mind would it be possible to add a license to the repo to make that easier?