Support multiple artifact dependency aliases to the same package

Cargo.toml

@@ -36,7 +36,7 @@ cargo-platform = { path = "crates/cargo-platform", version = "0.3.3" }
 cargo-test-macro = { version = "0.4.14", path = "crates/cargo-test-macro" }
 cargo-test-support = { version = "0.11.4", path = "crates/cargo-test-support" }
 cargo-util = { version = "0.2.32", path = "crates/cargo-util" }
-cargo-util-schemas = { version = "0.14.2", path = "crates/cargo-util-schemas" }
+cargo-util-schemas = { version = "0.15.0", path = "crates/cargo-util-schemas" }
 cargo-util-terminal = { version = "0.1.2", path = "crates/cargo-util-terminal" }
 cargo_metadata = "0.23.1"
 clap = "4.6.0"

crates/cargo-util-schemas/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cargo-util-schemas"
-version = "0.14.3"
+version = "0.15.0"
 rust-version = "1.97"  # MSRV:1
 edition.workspace = true
 license.workspace = true

crates/cargo-util-schemas/index.schema.json

@@ -180,7 +180,7 @@
           ]
         },
         "lib": {
-          "description": "Whether or not this is a library dependency.",
+          "description": "Legacy artifact dependency flag retained for index schema v3 compatibility.\n\nCargo ignores this field.",
           "type": "boolean",
           "default": false
         }

crates/cargo-util-schemas/manifest.schema.json

@@ -862,13 +862,6 @@
             }
           ]
         },
-        "lib": {
-          "description": "If set, the artifact should also be a dependency",
-          "type": [
-            "boolean",
-            "null"
-          ]
-        },
         "target": {
           "description": "A platform name, like `x86_64-apple-darwin`",
           "type": [
@@ -1483,4 +1476,4 @@
       ]
     }
   }
-}
+}

crates/cargo-util-schemas/src/index.rs

@@ -124,7 +124,9 @@ pub struct RegistryDependency<'a> {
     pub artifact: Option<Vec<Cow<'a, str>>>,
     /// The target for bindep.
     pub bindep_target: Option<Cow<'a, str>>,
-    /// Whether or not this is a library dependency.
+    /// Legacy artifact dependency flag retained for index schema v3 compatibility.
+    ///
+    /// Cargo ignores this field.
     #[serde(default)]
     pub lib: bool,
 }

crates/cargo-util-schemas/src/manifest/mod.rs

@@ -854,8 +854,6 @@ pub struct TomlDetailedDependency<P: Clone = String> {
 
     /// One or more of `bin`, `cdylib`, `staticlib`, `bin:<name>`.
     pub artifact: Option<StringOrVec>,
-    /// If set, the artifact should also be a dependency
-    pub lib: Option<bool>,
     /// A platform name, like `x86_64-apple-darwin`
     pub target: Option<String>,
 
@@ -892,7 +890,6 @@ impl<P: Clone> Default for TomlDetailedDependency<P> {
             package: Default::default(),
             public: Default::default(),
             artifact: Default::default(),
-            lib: Default::default(),
             target: Default::default(),
             _unused_keys: Default::default(),
         }

crates/crates-io/lib.rs

@@ -91,6 +91,7 @@ pub struct NewCrateDependency {
     pub artifact: Option<Vec<String>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub bindep_target: Option<String>,
+    /// Legacy artifact dependency flag retained for registry API compatibility.
     #[serde(default, skip_serializing_if = "std::ops::Not::not")]
     pub lib: bool,
 }

doc/book/src/reference/unstable.md

@@ -1024,20 +1024,23 @@ Artifact-dependencies adds the following keys to a dependency declaration in `Ca
   zoo = { version = "1.0", artifact = ["bin:cat", "bin:dog"]}
   ```
 
-- `lib` --- This is a Boolean value which indicates whether or not to also build the dependency's library as a normal Rust `lib` dependency.
-  This field can only be specified when `artifact` is specified.
-
-  The default for this field is `false` when `artifact` is specified.
-  If this is set to `true`, then the dependency's `[lib]` target will also be built for the platform target the declaring package is being built for.
-  This allows the package to use the dependency from Rust code like a normal dependency in addition to an artifact dependency.
-
-  Example:
+  To use both the library and an artifact from the same package, declare
+  two dependencies:
 
   ```toml
   [dependencies]
-  bar = { version = "1.0", artifact = "bin", lib = true }
+  bar = "1.0"
+  bar-bin = { package = "bar", version = "1.0", artifact = "bin" }
   ```
 
+  The normal dependency and artifact dependency have different dependency
+  graphs. Features enabled for `bar` are not enabled for `bar-bin`, and
+  features enabled for `bar-bin` are not enabled for `bar`, unless the same
+  features are enabled on both dependencies.
+
+  The dependency-level `lib` key has been removed. Cargo rejects manifests
+  that set it; use separate normal and artifact dependencies instead.
+
 - `target` --- The platform target to build the dependency for.
   This field can only be specified when `artifact` is specified.
 
@@ -1053,6 +1056,15 @@ Artifact-dependencies adds the following keys to a dependency declaration in `Ca
   same-target = { version = "1.0", artifact = "bin", target = "target" }
   ```
 
+  To build artifacts from the same package for multiple target platforms,
+  declare each alias separately:
+
+  ```toml
+  [build-dependencies]
+  firmware-x86 = { package = "firmware", version = "1.0", artifact = "bin", target = "x86_64-unknown-none" }
+  firmware-arm = { package = "firmware", version = "1.0", artifact = "bin", target = "thumbv7em-none-eabihf" }
+  ```
+
 ### artifact-dependencies: Environment variables
 
 After building an artifact dependency, Cargo provides the following environment variables that you can use to access the artifact:
@@ -1127,22 +1139,25 @@ fn main() {
 }
 ```
 
-#### Example: use _binary_ artifact and its library in a binary
+#### Example: use a binary artifact and its library
 
-The `Cargo.toml` in the consuming package, building the `bar` binary for inclusion
-as artifact while making it available as library as well…
+The `Cargo.toml` in the consuming package can declare both a normal dependency
+and an artifact dependency on the same package:
 
 ```toml
 [dependencies]
-bar = { artifact = "bin", version = "1.0", lib = true }
+bar = "1.0"
+bar-bin = { package = "bar", version = "1.0", artifact = "bin" }
 ```
 
-…along with the executable using `main.rs`.
+The normal dependency is available to Rust code under its dependency name, and
+the artifact is available through the environment variable for the artifact
+dependency alias:
 
 ```rust
 fn main() {
     bar::init();
-    command::run(env!("CARGO_BIN_FILE_BAR"));
+    command::run(env!("CARGO_BIN_FILE_BAR_BIN_bar"));
 }
 ```
 

src/compiler/standard_lib.rs

@@ -210,6 +210,7 @@ fn generate_roots(
                 /*dep_hash*/ 0,
                 IsArtifact::No,
                 None,
+                None,
                 false,
             ));
         }

src/compiler/unit.rs

@@ -130,6 +130,9 @@ pub struct UnitInner {
     ///
     /// [`FeaturesFor::ArtifactDep`]: crate::resolver::features::FeaturesFor::ArtifactDep
     pub artifact_target_for_features: Option<CompileTarget>,
+    /// The dependency name that introduced this artifact dependency feature
+    /// graph.
+    pub artifact_dep_name_for_features: Option<InternedString>,
 
     /// Skip compiling this unit because `--compile-time-deps` flag is set and
     /// this is not a compile time dependency.
@@ -212,6 +215,10 @@ impl fmt::Debug for Unit {
                 "artifact_target_for_features",
                 &self.artifact_target_for_features,
             )
+            .field(
+                "artifact_dep_name_for_features",
+                &self.artifact_dep_name_for_features,
+            )
             .field("is_std", &self.is_std)
             .field("dep_hash", &self.dep_hash)
             .finish()
@@ -261,6 +268,7 @@ impl UnitInterner {
         dep_hash: u64,
         artifact: IsArtifact,
         artifact_target_for_features: Option<CompileTarget>,
+        artifact_dep_name_for_features: Option<InternedString>,
         skip_non_compile_time_dep: bool,
     ) -> Unit {
         let target = match (is_std, target.kind()) {
@@ -298,6 +306,7 @@ impl UnitInterner {
             dep_hash,
             artifact,
             artifact_target_for_features,
+            artifact_dep_name_for_features,
             skip_non_compile_time_dep,
         });
         Unit { inner }