diff --git a/src/application/ReferenceSourceVcsAdapter.ts b/src/application/ReferenceSourceVcsAdapter.ts
index c47cd60f3c..cd372e230d 100644
--- a/src/application/ReferenceSourceVcsAdapter.ts
+++ b/src/application/ReferenceSourceVcsAdapter.ts
@@ -9,6 +9,7 @@ import {
   RegularFileCleanupFailure,
   retryRegularFileCleanup,
 } from "./RegularFileRead.js";
+import { referenceSourceResourceFailure } from "../reference/ReferenceSourceReaderErrors.js";
 import type { ReferenceSourceReaderError } from "../reference/ReferenceSourceReaderTypes.js";
 
 export type ReferenceSourceVcsInfo =
@@ -59,13 +60,7 @@ export const readReferenceSourceVcs = async (
     });
   } catch (cause: unknown) {
     if (!(cause instanceof ArtifactReaderFailure)) throw cause;
-    return err({
-      tag: "reference-source-reader",
-      code: cause.reason === "cancelled" ? "cancelled" : "io",
-      message: cause.message,
-      ...(cause.cleanup === undefined ? {} : { cleanup: cause.cleanup }),
-      cause,
-    });
+    return err(referenceSourceResourceFailure(cause));
   }
 };
 
diff --git a/src/reference/ReferenceSourceReader.ts b/src/reference/ReferenceSourceReader.ts
index 4af7da9de2..0b43b55f96 100644
--- a/src/reference/ReferenceSourceReader.ts
+++ b/src/reference/ReferenceSourceReader.ts
@@ -19,6 +19,7 @@ import {
   noFollowOpenSupported,
   prepareRoot,
 } from "./ReferenceSourceReaderValidate.js";
+import { referenceSourceResourceFailure } from "./ReferenceSourceReaderErrors.js";
 
 const PATH_RACE_LIMITATION =
   "Path identity is revalidated around operations; Node lacks portable descriptor-relative openat traversal, so a syscall-boundary pathname race remains.";
@@ -33,13 +34,7 @@ export const readReferenceSource = async (
     return await resources.run(() => readSource(root, resources, options));
   } catch (cause: unknown) {
     if (!(cause instanceof ArtifactReaderFailure)) throw cause;
-    return err({
-      tag: "reference-source-reader",
-      code: cause.reason === "cancelled" ? "cancelled" : "io",
-      message: cause.message,
-      ...(cause.cleanup === undefined ? {} : { cleanup: cause.cleanup }),
-      cause,
-    });
+    return err(referenceSourceResourceFailure(cause));
   }
 };
 
diff --git a/src/reference/ReferenceSourceReaderErrors.ts b/src/reference/ReferenceSourceReaderErrors.ts
index 2c826b4c96..85e02be759 100644
--- a/src/reference/ReferenceSourceReaderErrors.ts
+++ b/src/reference/ReferenceSourceReaderErrors.ts
@@ -1,3 +1,4 @@
+import type { ArtifactReaderFailure } from "../artifacts/ArtifactReader.js";
 import type {
   ReferenceSourceEntry,
   ReferenceSourceFailureCode,
@@ -16,6 +17,17 @@ export const failure = (
 export const cancelled = (): ReferenceSourceReaderError =>
   failure("cancelled", "Reference source traversal cancelled");
 
+/** Project resource failures into the reference-source error contract. */
+export const referenceSourceResourceFailure = (
+  cause: ArtifactReaderFailure,
+): ReferenceSourceReaderError => ({
+  tag: "reference-source-reader",
+  code: cause.reason === "cancelled" ? "cancelled" : "io",
+  message: cause.message,
+  ...(cause.cleanup === undefined ? {} : { cleanup: cause.cleanup }),
+  cause,
+});
+
 export const safeSize = (size: bigint): number | undefined => {
   const value = Number(size);
   return Number.isSafeInteger(value) && value >= 0 ? value : undefined;