feat(test): Manual publishes set 'rust_version' in Index

Author: epage

crates/cargo-test-support/src/publish.rs

@@ -165,6 +165,7 @@ pub(crate) fn create_index_line(
     features: crate::registry::FeatureMap,
     yanked: bool,
     links: Option<String>,
+    rust_version: Option<&str>,
     v: Option<u32>,
 ) -> String {
     // This emulates what crates.io does to retain backwards compatibility.
@@ -185,6 +186,9 @@ pub(crate) fn create_index_line(
     if let Some(v) = v {
         json["v"] = serde_json::json!(v);
     }
+    if let Some(rust_version) = rust_version {
+        json["rust_version"] = serde_json::json!(rust_version);
+    }
 
     json.to_string()
 }

crates/cargo-test-support/src/registry.rs

@@ -1144,6 +1144,7 @@ fn save_new_crate(
         false,
         new_crate.links,
         None,
+        None,
     );
 
     write_to_index(registry_path, &new_crate.name, line, false);
@@ -1400,6 +1401,7 @@ impl Package {
             self.features.clone(),
             self.yanked,
             self.links.clone(),
+            self.rust_version.as_deref(),
             self.v,
         );