Exercise crates_vendor in bzlmod hello_world example

examples/bzlmod/hello_world/.gitignore

@@ -0,0 +1 @@
+/bazel-*

examples/bzlmod/hello_world/BUILD.bazel

@@ -5,6 +5,9 @@ package(default_visibility = ["//visibility:public"])
 rust_binary(
     name = "hello_world",
     srcs = ["src/main.rs"],
+    deps = [
+        "//third-party/crates:anyhow",
+    ],
 )
 
 rust_doc(

examples/bzlmod/hello_world/MODULE.bazel

@@ -5,6 +5,8 @@ module(
     version = "0.0.0",
 )
 
+bazel_dep(name = "bazel_skylib", version = "1.5.0")
+
 bazel_dep(name = "rules_rust", version = "0.0.0")
 local_path_override(
     module_name = "rules_rust",
@@ -19,3 +21,6 @@ use_repo(
 )
 
 register_toolchains("@rust_toolchains//:all")
+
+crate_repositories = use_extension("//third-party:extension.bzl", "crate_repositories")
+use_repo(crate_repositories, "vendor__anyhow-1.0.77")

examples/bzlmod/hello_world/src/main.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-fn main() {
+fn main() -> anyhow::Result<()> {
     println!("Hello, world!");
+    Ok(())
 }

examples/bzlmod/hello_world/third-party/BUILD.bazel

@@ -0,0 +1,10 @@
+load("@rules_rust//crate_universe:defs.bzl", "crates_vendor")
+
+crates_vendor(
+    name = "vendor",
+    cargo_lockfile = "//third-party:Cargo.lock",
+    generate_build_scripts = True,
+    manifests = ["//third-party:Cargo.toml"],
+    mode = "remote",
+    tags = ["manual"],
+)

examples/bzlmod/hello_world/third-party/Cargo.toml

@@ -0,0 +1,12 @@
+[workspace]
+[package]
+name = "third-party"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[lib]
+path = "/dev/null"
+
+[dependencies]
+anyhow = "1.0.77"

examples/bzlmod/hello_world/third-party/extension.bzl

@@ -0,0 +1,14 @@
+"""Module extensions for using vendored crates with bzlmod"""
+
+load("//third-party/crates:defs.bzl", _crate_repositories = "crate_repositories")
+
+def _crate_repositories_impl(module_ctx):
+    direct_deps = _crate_repositories()
+    return module_ctx.extension_metadata(
+        root_module_direct_deps = [repo.repo for repo in direct_deps],
+        root_module_direct_dev_deps = [],
+    )
+
+crate_repositories = module_extension(
+    implementation = _crate_repositories_impl,
+)