feat: Expose 'rust_version' in the Summary

Author: epage

src/cargo/core/resolver/version_prefs.rs

@@ -100,7 +100,15 @@ mod test {
         let pkg_id = pkgid(name, version);
         let config = Config::default().unwrap();
         let features = BTreeMap::new();
-        Summary::new(&config, pkg_id, Vec::new(), &features, None::<&String>).unwrap()
+        Summary::new(
+            &config,
+            pkg_id,
+            Vec::new(),
+            &features,
+            None::<&String>,
+            None::<&String>,
+        )
+        .unwrap()
     }
 
     fn describe(summaries: &Vec<Summary>) -> String {

src/cargo/core/summary.rs

@@ -25,6 +25,7 @@ struct Inner {
     features: Rc<FeatureMap>,
     checksum: Option<String>,
     links: Option<InternedString>,
+    rust_version: Option<InternedString>,
 }
 
 impl Summary {
@@ -34,6 +35,7 @@ impl Summary {
         dependencies: Vec<Dependency>,
         features: &BTreeMap<InternedString, Vec<InternedString>>,
         links: Option<impl Into<InternedString>>,
+        rust_version: Option<impl Into<InternedString>>,
     ) -> CargoResult<Summary> {
         // ****CAUTION**** If you change anything here that may raise a new
         // error, be sure to coordinate that change with either the index
@@ -55,6 +57,7 @@ impl Summary {
                 features: Rc::new(feature_map),
                 checksum: None,
                 links: links.map(|l| l.into()),
+                rust_version: rust_version.map(|l| l.into()),
             }),
         })
     }
@@ -85,6 +88,10 @@ impl Summary {
         self.inner.links
     }
 
+    pub fn rust_version(&self) -> Option<InternedString> {
+        self.inner.rust_version
+    }
+
     pub fn override_id(mut self, id: PackageId) -> Summary {
         Rc::make_mut(&mut self.inner).package_id = id;
         self

src/cargo/sources/registry/index.rs

@@ -814,7 +814,7 @@ impl IndexSummary {
             features2,
             yanked,
             links,
-            rust_version: _,
+            rust_version,
             v,
         } = serde_json::from_slice(line)?;
         let v = v.unwrap_or(1);
@@ -829,7 +829,7 @@ impl IndexSummary {
                 features.entry(name).or_default().extend(values);
             }
         }
-        let mut summary = Summary::new(config, pkgid, deps, &features, links)?;
+        let mut summary = Summary::new(config, pkgid, deps, &features, links, rust_version)?;
         summary.set_checksum(cksum);
         Ok(IndexSummary {
             summary,

src/cargo/sources/registry/mod.rs

@@ -293,7 +293,6 @@ pub struct RegistryPackage<'a> {
     ///
     /// Added in 2023 (see <https://github.com/rust-lang/crates.io/pull/6267>),
     /// can be `None` if published before then or if not set in the manifest.
-    #[allow(dead_code)]
     rust_version: Option<InternedString>,
     /// The schema version for this entry.
     ///

src/cargo/util/toml/mod.rs

@@ -2367,6 +2367,7 @@ impl TomlManifest {
             deps,
             me.features.as_ref().unwrap_or(&empty_features),
             package.links.as_deref(),
+            rust_version.as_deref().map(InternedString::new),
         )?;
 
         let metadata = ManifestMetadata {