fix(reference): preserve physical failures across late cancellation (#10072)

* fix(reference): preserve physical failures across late cancellation

* fix(reference): retain late cancellation alongside read failures

* fix(reference): preserve metadata errors through cancellation

* fix(reference): retain directory failure identity

* fix(reference): preserve parallel physical and cancellation outcomes

* fix(reference): preserve optional Git metadata absence

src/reference/ReferenceSourceReader.ts

@@ -33,12 +33,23 @@ export const readReferenceSource = async (
   resources: ArtifactResourceScope,
   options: ReferenceSourceReaderOptions = {},
 ): Promise<ReferenceSourceResult<ReferenceSourceRead>> => {
+  let result: ReferenceSourceResult<ReferenceSourceRead>;
   try {
-    return await resources.run(() => readSource(root, resources, options));
+    result = await resources.run(() => readSource(root, resources, options));
   } catch (cause: unknown) {
     if (!(cause instanceof ArtifactReaderFailure)) throw cause;
-    return err(referenceSourceResourceFailure(cause));
+    result = err(referenceSourceResourceFailure(cause));
   }
+  if (
+    !result.ok &&
+    result.error.code !== "cancelled" &&
+    options.signal?.aborted
+  )
+    return err({
+      ...result.error,
+      secondaryCancellation: { cause: options.signal.reason },
+    });
+  return result;
 };
 
 const readSource = async (
@@ -99,6 +110,9 @@ const readSource = async (
       tag: "reference-source-reader",
       code: "io",
       message: state.rootFailure.message,
+      ...(state.rootFailureCause === undefined
+        ? {}
+        : { cause: state.rootFailureCause.value }),
       partial: read,
     });
   return traversal.ok ? ok(read) : err({ ...traversal.error, partial: read });