chore(pm): clarify resolver provider diagnostics

Author: elrrrrrrr

crates/ruborist/src/resolver/builder.rs

@@ -1683,6 +1683,11 @@ where
             }
 
             let Some(done) = fetches.next().await else {
+                tracing::warn!(
+                    full_waiters = state.full_waiters.values().map(Vec::len).sum::<usize>(),
+                    version_waiters = state.version_waiters.values().map(Vec::len).sum::<usize>(),
+                    "manifest fetch stream ended with pending resolver waiters; falling back to sequential resolution"
+                );
                 let mut fallback = Vec::new();
                 for (_, waiters) in state.full_waiters.drain() {
                     fallback.extend(waiters);

crates/ruborist/src/service/manifest.rs

@@ -68,11 +68,32 @@ fn parse_full_manifest_with_core_sync(
         .map_err(|e| anyhow!("JSON parse error: {e}"))?;
     manifest.raw = raw_bytes;
 
-    let speculative = spec.and_then(|spec| {
-        resolve_target_version((&manifest).into(), &spec)
-            .ok()
-            .and_then(|version| manifest.get_core_version(&version).map(|core| (spec, core)))
-    });
+    let speculative = match spec {
+        Some(spec) => match resolve_target_version((&manifest).into(), &spec) {
+            Ok(version) => match manifest.get_core_version(&version) {
+                Some(core) => Some((spec, core)),
+                None => {
+                    tracing::trace!(
+                        package = %manifest.name,
+                        spec = %spec,
+                        version = %version,
+                        "speculative manifest extract missed resolved version"
+                    );
+                    None
+                }
+            },
+            Err(error) => {
+                tracing::trace!(
+                    package = %manifest.name,
+                    spec = %spec,
+                    error = %error,
+                    "speculative manifest version resolution failed"
+                );
+                None
+            }
+        },
+        None => None,
+    };
 
     Ok((manifest, speculative))
 }

crates/ruborist/src/service/provider.rs

@@ -73,6 +73,9 @@ pub enum ManifestJobDone {
 }
 
 /// Lower-level manifest provider used by the demand BFS loop.
+///
+/// Resolver workers clone the provider before spawning jobs, so implementors
+/// should keep `Clone` cheap (for example by storing shared state behind `Arc`).
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
 #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 pub trait ManifestProvider: RegistryClient + Clone + Send + Sync + 'static {