diff --git a/src/javascript/sourceMaps/SourceMapCommand.test.ts b/src/javascript/sourceMaps/SourceMapCommand.test.ts
index cdca518743..ae2b338408 100644
--- a/src/javascript/sourceMaps/SourceMapCommand.test.ts
+++ b/src/javascript/sourceMaps/SourceMapCommand.test.ts
@@ -1,5 +1,5 @@
 import { access } from "node:fs/promises";
-import { expect, it, vi } from "vitest";
+import { afterEach, expect, it, vi } from "vitest";
 import {
   AnalysisCancelledError,
   AnalysisResourceConstraintError,
@@ -14,8 +14,18 @@ import { WEB_SOURCE_MAP_LIMITS } from "../../domain/webSourceLocation.js";
 import {
   runSourceMapCommand,
   SOURCE_MAP_CODEC_MEMORY_LIMIT_BYTES,
+  type SourceMapCleanupRetention,
 } from "./SourceMapCommand.js";
 
+const unexpectedCleanup: SourceMapCleanupRetention = {};
+afterEach(async () => {
+  const owner = unexpectedCleanup.owner;
+  const failure = await owner?.close();
+  if (failure !== undefined) throw failure;
+  unexpectedCleanup.owner = undefined;
+  expect(owner).toBeUndefined();
+});
+
 const runChild = (
   signal: AbortSignal | undefined,
   script: string,
@@ -44,6 +54,7 @@ const runChild = (
         return child;
       },
     },
+    unexpectedCleanup,
   );
 
 const exitsAfterHoldingOutput =
@@ -65,6 +76,7 @@ it("preserves the exact object reason for an already-aborted caller", async () =
         throw new Error("must not launch");
       },
     },
+    unexpectedCleanup,
   );
   expect(result.ok).toBe(false);
   if (result.ok) throw new Error("expected cancellation");
@@ -72,6 +84,67 @@ it("preserves the exact object reason for an already-aborted caller", async () =
   expect(result.error.cause).toBe(reason);
 });
 
+it.each([null, { caller: "late source-map cancellation" }])(
+  "retains a late caller reason %j when runtime cleanup first fails",
+  async (reason) => {
+    const root = await PrivateRuntimeRoot.create({
+      prefix: "rea-source-map-late-cleanup-test-",
+    });
+    const controller = new AbortController();
+    let cleanupAttempts = 0;
+    const retainedCleanup: SourceMapCleanupRetention = {};
+    try {
+      const result = await runSourceMapCommand(
+        "{}",
+        "/probe/source.map",
+        { signal: controller.signal },
+        {
+          prepareOwnership: async () => {},
+          createRuntime: async () => ({
+            path: root.path,
+            close: async () => {
+              cleanupAttempts += 1;
+              if (cleanupAttempts === 1) {
+                controller.abort(reason);
+                throw new Error("controlled late cleanup failure");
+              }
+              await root.close();
+            },
+          }),
+          launcher: async (options) =>
+            spawnOwnedProviderProcess({
+              ...options,
+              arguments: ["-e", 'process.stdout.write("complete")'],
+            }),
+        },
+        retainedCleanup,
+      );
+      expect(result.ok).toBe(false);
+      if (result.ok)
+        throw new Error("expected cancellation with cleanup failure");
+      expect(result.error.cleanupPrimary).toBeInstanceOf(
+        AnalysisCancelledError,
+      );
+      expect(result.error.cleanupPrimary?.cause).toBe(reason);
+      expect(result.error.cleanupResources).toEqual([root.path]);
+      expect(result.error.cleanupIncomplete).toBe(true);
+      expect(retainedCleanup.owner).toBeDefined();
+      await retainedCleanup.owner?.close();
+      expect(result.error.cleanupIncomplete).toBe(false);
+      expect(result.error.cleanupResources).toEqual([]);
+      expect(result.error.cleanupPrimary?.cause).toBe(reason);
+    } finally {
+      await retainedCleanup.owner?.close();
+      await root.close();
+    }
+  },
+);
+
+it("returns completed codec output after successful cleanup", async () => {
+  const result = await runChild(undefined, 'process.stdout.write("complete")');
+  expect(result).toEqual({ ok: true, value: "complete" });
+});
+
 it("preserves exact caller reason when cancellation precedes process exit", async () => {
   const reason = { caller: "active source-map cancellation" };
   const controller = new AbortController();
@@ -222,6 +295,7 @@ it("preserves an observed process-memory limit over the codec exit status", asyn
           return spawned;
         },
       },
+      unexpectedCleanup,
     );
   } finally {
     waitSpy.mockRestore();
@@ -266,6 +340,7 @@ it("keeps a timeout distinct from caller cancellation", async () => {
           throw new Error("launcher settled after deadline");
         },
       },
+      unexpectedCleanup,
     );
     expect(result.ok).toBe(false);
     if (result.ok) throw new Error("expected timeout");
@@ -301,6 +376,7 @@ it("applies a non-default decode deadline and releases its runtime", async () =>
           throw new Error("launcher settled after deadline");
         },
       },
+      unexpectedCleanup,
       250,
     );
     expect(result.ok).toBe(false);
diff --git a/src/javascript/sourceMaps/SourceMapCommand.ts b/src/javascript/sourceMaps/SourceMapCommand.ts
index 3cf7485560..3da5b9eef6 100644
--- a/src/javascript/sourceMaps/SourceMapCommand.ts
+++ b/src/javascript/sourceMaps/SourceMapCommand.ts
@@ -4,6 +4,7 @@ import { join } from "node:path";
 import { fileURLToPath } from "node:url";
 import type { ExecutionOptions } from "../../application/AnalysisProvider.js";
 import { AnalysisError } from "../../domain/analysisErrorBase.js";
+import { analysisErrorWithCleanupFailure } from "../../domain/analysisErrorCleanup.js";
 import {
   AnalysisCancelledError,
   AnalysisOutputError,
@@ -62,9 +63,12 @@ export interface SourceMapDecoderDependencies {
 }
 
 export interface SourceMapCleanupOwner {
-  close(
-    previousError: string | null,
-  ): Promise<ProviderCleanupError | undefined>;
+  close(): Promise<ProviderCleanupError | undefined>;
+}
+
+/** The caller retains retry authority independently of the returned error. */
+export interface SourceMapCleanupRetention {
+  owner?: SourceMapCleanupOwner | undefined;
 }
 
 type CodecPhysicalObservation =
@@ -88,7 +92,6 @@ type CodecOutcome =
 
 export class SourceMapCleanupFailure extends ProviderCleanupError {
   constructor(
-    readonly cleanupOwner: SourceMapCleanupOwner,
     resources: readonly string[],
     diagnostics: Readonly<Record<string, JsonValue>>,
   ) {
@@ -102,6 +105,7 @@ export const runSourceMapCommand = async (
   path: string,
   options: ExecutionOptions | undefined,
   dependencies: SourceMapDecoderDependencies,
+  retainedCleanup: SourceMapCleanupRetention,
   decodeTimeoutMs: number = DEFAULT_WEB_SOURCE_MAP_DECODE_TIMEOUT_MS,
 ): Promise<Result<string, AnalysisError>> => {
   try {
@@ -141,13 +145,26 @@ export const runSourceMapCommand = async (
     command.dispose();
     deadline.dispose();
   }
-  const cleanup = await command.close(result.ok ? null : result.error.message);
-  if (cleanup !== undefined) return err(cleanup);
-  return result.ok && options?.signal?.aborted
-    ? err(
-        new AnalysisCancelledError(OPERATION, { cause: options.signal.reason }),
-      )
-    : result;
+  const cleanup = await command.close();
+  const completed =
+    result.ok && options?.signal?.aborted
+      ? err(
+          new AnalysisCancelledError(OPERATION, {
+            cause: options.signal.reason,
+          }),
+        )
+      : result;
+  if (cleanup === undefined) return completed;
+  retainedCleanup.owner = command;
+  return completed.ok
+    ? err(cleanup)
+    : err(
+        analysisErrorWithCleanupFailure(
+          completed.error,
+          cleanup,
+          OPERATION,
+        ).bindCleanupDependencies([cleanup], command),
+      );
 };
 
 class OwnedCodec implements SourceMapCleanupOwner {
@@ -471,9 +488,7 @@ class OwnedCodec implements SourceMapCleanupOwner {
     ];
   }
 
-  async close(
-    previousError: string | null,
-  ): Promise<ProviderCleanupError | undefined> {
+  async close(): Promise<ProviderCleanupError | undefined> {
     const failures: string[] = [];
     let processReleased = this.#supervisor === undefined;
     if (this.#supervisor !== undefined) {
@@ -497,10 +512,9 @@ class OwnedCodec implements SourceMapCleanupOwner {
       this.#cleanupAnchor = undefined;
       return undefined;
     }
-    const failure = new SourceMapCleanupFailure(this, this.cleanupResources, {
+    const failure = new SourceMapCleanupFailure(this.cleanupResources, {
       map_path: this.path,
       cleanup_failures: failures,
-      previous_error: previousError,
       codec_pid: this.#supervisor?.launch.process.pid ?? null,
     }).bindCleanupResourceOwner(this);
     if (this.#cleanupAnchor === undefined) this.#cleanupAnchor = failure;
diff --git a/src/javascript/sourceMaps/SourceMapDecoder.test.ts b/src/javascript/sourceMaps/SourceMapDecoder.test.ts
index dc062ac01b..9236716b0f 100644
--- a/src/javascript/sourceMaps/SourceMapDecoder.test.ts
+++ b/src/javascript/sourceMaps/SourceMapDecoder.test.ts
@@ -67,19 +67,30 @@ it("retains failed cleanup ownership and retries it before another decode", asyn
     expect(failed.ok).toBe(false);
     if (failed.ok)
       throw new Error("expected physical failure with cleanup failure");
-    expect(failed.error).toBeInstanceOf(SourceMapCleanupFailure);
-    if (!(failed.error instanceof SourceMapCleanupFailure))
-      throw new Error("expected source-map cleanup ownership");
-    expect(failed.error.cleanupOwner).toBeDefined();
+    const primary = failed.error.cleanupPrimary;
+    expect(primary).toMatchObject({
+      _tag: "ProviderAdapterError",
+      diagnostics: {
+        exit_code: 7,
+        stderr: "physical exit 7",
+      },
+    });
+    expect(primary?.capturedOutput?.stderr).toBe("physical exit 7");
+    expect(failed.error.capturedOutput).toEqual(primary?.capturedOutput);
+    expect(failed.error.cause).toBeInstanceOf(AggregateError);
+    expect((failed.error.cause as AggregateError).errors[0]).toBe(primary);
     expect(failed.error.cleanupResources).toEqual([root.path]);
     expect(failed.error.diagnostics).toMatchObject({
-      cleanup_failures: ["injected root cleanup failure"],
-    });
-    expect(failed.error.diagnostics).toMatchObject({
-      previous_error: expect.stringContaining(
-        "source-map-decoder adapter failed",
-      ),
+      primary_error: { code: "execution_failure" },
+      cleanup_error: {
+        details: {
+          diagnostics: {
+            cleanup_failures: ["injected root cleanup failure"],
+          },
+        },
+      },
     });
+    expect(projectAnalysisError(failed.error).code).toBe("cleanup_incomplete");
     await expect(access(root.path)).resolves.toBeUndefined();
 
     const invalidInput = { ...input, text: null } as unknown as typeof input;
@@ -92,11 +103,16 @@ it("retains failed cleanup ownership and retries it before another decode", asyn
     await expect(access(root.path)).rejects.toMatchObject({ code: "ENOENT" });
     expect(failed.error.cleanupIncomplete).toBe(false);
     expect(failed.error.cleanupResources).toEqual([]);
-    expect(projectAnalysisError(failed.error).code).not.toBe(
-      "cleanup_incomplete",
-    );
+    expect(projectAnalysisError(failed.error).code).toBe("execution_failure");
+    expect(failed.error.cleanupPrimary).toBe(primary);
     expect(failed.error.diagnostics).toMatchObject({
-      cleanup_failures: ["injected root cleanup failure"],
+      cleanup_error: {
+        details: {
+          diagnostics: {
+            cleanup_failures: ["injected root cleanup failure"],
+          },
+        },
+      },
     });
   } finally {
     await decoder.close();
@@ -108,6 +124,7 @@ it("settles every source-map cleanup failure when final close releases the exact
     prefix: "rea-source-map-final-cleanup-test-",
   });
   let attempts = 0;
+  const launchCause = new Error("controlled launch failure");
   const decoder = new SourceMapDecoder({
     prepareOwnership: async () => {},
     createRuntime: async () => ({
@@ -120,12 +137,16 @@ it("settles every source-map cleanup failure when final close releases the exact
       },
     }),
     launcher: async () => {
-      throw new Error("controlled launch failure");
+      throw launchCause;
     },
   });
   try {
     const initial = await decoder.trace(input);
     if (initial.ok) throw new Error("expected initial cleanup failure");
+    expect(initial.error.cleanupPrimary?.cause).toBe(launchCause);
+    expect((initial.error.cause as AggregateError).errors[0]).toBe(
+      initial.error.cleanupPrimary,
+    );
     const retry = await decoder.trace(input);
     if (retry.ok) throw new Error("expected retry cleanup failure");
     for (const failure of [initial.error, retry.error]) {
@@ -139,11 +160,22 @@ it("settles every source-map cleanup failure when final close releases the exact
     for (const failure of [initial.error, retry.error]) {
       expect(failure.cleanupIncomplete).toBe(false);
       expect(failure.cleanupResources).toEqual([]);
-      expect(projectAnalysisError(failure).code).not.toBe("cleanup_incomplete");
-      expect(failure.diagnostics?.cleanup_failures).toEqual([
-        expect.stringContaining("runtime cleanup attempt"),
-      ]);
+      expect(projectAnalysisError(failure).code).toBe("execution_failure");
     }
+    expect(initial.error.cleanupPrimary?.cause).toBe(launchCause);
+    expect(initial.error.diagnostics).toMatchObject({
+      cleanup_error: {
+        details: {
+          diagnostics: {
+            cleanup_failures: ["runtime cleanup attempt 1 failed"],
+          },
+        },
+      },
+    });
+    expect(retry.error).toBeInstanceOf(SourceMapCleanupFailure);
+    expect(retry.error.diagnostics?.cleanup_failures).toEqual([
+      "runtime cleanup attempt 2 failed",
+    ]);
   } finally {
     await decoder.close();
   }
diff --git a/src/javascript/sourceMaps/SourceMapDecoder.ts b/src/javascript/sourceMaps/SourceMapDecoder.ts
index 4159330ea1..08eca6a1c5 100644
--- a/src/javascript/sourceMaps/SourceMapDecoder.ts
+++ b/src/javascript/sourceMaps/SourceMapDecoder.ts
@@ -22,9 +22,9 @@ import {
 } from "./SourceMapCodecProtocol.js";
 import {
   SOURCE_MAP_CODEC_MEMORY_LIMIT_BYTES,
-  SourceMapCleanupFailure,
   runSourceMapCommand,
   type SourceMapCleanupOwner,
+  type SourceMapCleanupRetention,
   type SourceMapDecoderDependencies,
 } from "./SourceMapCommand.js";
 import { ProviderCleanupError } from "../../domain/providerCleanupError.js";
@@ -114,18 +114,18 @@ export class SourceMapDecoder implements WebSourceMapPort {
         new AnalysisCancelledError(OPERATION, { cause: options.signal.reason }),
       );
     const serialized = encoded.join("");
+    const retainedCleanup: SourceMapCleanupRetention = {};
     const response = await runSourceMapCommand(
       serialized,
       input.path,
       options,
       this.dependencies,
+      retainedCleanup,
       input.decodeTimeoutMs ?? DEFAULT_WEB_SOURCE_MAP_DECODE_TIMEOUT_MS,
     );
-    if (!response.ok) {
-      if (response.error instanceof SourceMapCleanupFailure)
-        this.#pendingCleanup = response.error.cleanupOwner;
-      return response;
-    }
+    if (retainedCleanup.owner !== undefined)
+      this.#pendingCleanup = retainedCleanup.owner;
+    if (!response.ok) return response;
     let value: unknown;
     try {
       value = JSON.parse(response.value);
@@ -174,7 +174,7 @@ export class SourceMapDecoder implements WebSourceMapPort {
   async #retryCleanup(): Promise<AnalysisError | undefined> {
     const pending = this.#pendingCleanup;
     if (pending === undefined) return undefined;
-    const failure = await pending.close(null);
+    const failure = await pending.close();
     if (failure !== undefined) return failure;
     this.#pendingCleanup = undefined;
     return undefined;
diff --git a/tests/boundary/javascript/sourceMapPreparation.test.ts b/tests/boundary/javascript/sourceMapPreparation.test.ts
index 5d9b01ff05..904462079f 100644
--- a/tests/boundary/javascript/sourceMapPreparation.test.ts
+++ b/tests/boundary/javascript/sourceMapPreparation.test.ts
@@ -2,7 +2,10 @@ import { expect, it, vi } from "vitest";
 import { AnalysisCancelledError } from "../../../src/domain/analysisErrorCore.js";
 import { ProviderAdapterError } from "../../../src/domain/providerAdapterError.js";
 import { ProviderCleanupError } from "../../../src/domain/providerCleanupError.js";
-import { runSourceMapCommand } from "../../../src/javascript/sourceMaps/SourceMapCommand.js";
+import {
+  runSourceMapCommand,
+  type SourceMapCleanupRetention,
+} from "../../../src/javascript/sourceMaps/SourceMapCommand.js";
 
 it.each([
   null,
@@ -11,6 +14,7 @@ it.each([
   "preserves opaque cancellation during ownership preparation: %s",
   async (reason) => {
     const controller = new AbortController();
+    const retainedCleanup: SourceMapCleanupRetention = {};
     const createRuntime = vi.fn(async () => {
       throw new Error("Cancelled preparation must not acquire a runtime");
     });
@@ -29,7 +33,9 @@ it.each([
         createRuntime,
         launcher,
       },
+      retainedCleanup,
     );
+    expect(retainedCleanup.owner).toBeUndefined();
     if (result.ok) throw new Error("Preparation must return cancellation");
     expect(result.error).toBeInstanceOf(AnalysisCancelledError);
     expect(result.error.cause).toBe(reason);
@@ -46,19 +52,27 @@ it.each([
 
 it("retains diagnostics for an unknown ownership preparation failure", async () => {
   const cause = new Error("unexpected ownership failure");
+  const retainedCleanup: SourceMapCleanupRetention = {};
   const createRuntime = vi.fn(async () => {
     throw new Error("Failed preparation must not acquire a runtime");
   });
   const launcher = vi.fn(async () => {
     throw new Error("Failed preparation must not launch a codec");
   });
-  const result = await runSourceMapCommand("{}", "/selected.map", undefined, {
-    prepareOwnership: async () => {
-      throw cause;
+  const result = await runSourceMapCommand(
+    "{}",
+    "/selected.map",
+    undefined,
+    {
+      prepareOwnership: async () => {
+        throw cause;
+      },
+      createRuntime,
+      launcher,
     },
-    createRuntime,
-    launcher,
-  });
+    retainedCleanup,
+  );
+  expect(retainedCleanup.owner).toBeUndefined();
   if (result.ok) throw new Error("Preparation must return its failure");
   expect(result.error).toBeInstanceOf(ProviderAdapterError);
   expect(result.error.cause).toBe(cause);
diff --git a/tests/boundary/javascript/sourceMapRuntimeAvailability.test.ts b/tests/boundary/javascript/sourceMapRuntimeAvailability.test.ts
index 753a3bd470..19970876f7 100644
--- a/tests/boundary/javascript/sourceMapRuntimeAvailability.test.ts
+++ b/tests/boundary/javascript/sourceMapRuntimeAvailability.test.ts
@@ -1,6 +1,9 @@
 import { expect, it } from "vitest";
 import { projectAnalysisError } from "../../../src/domain/analysisErrorProjection.js";
-import { runSourceMapCommand } from "../../../src/javascript/sourceMaps/SourceMapCommand.js";
+import {
+  runSourceMapCommand,
+  type SourceMapCleanupRetention,
+} from "../../../src/javascript/sourceMaps/SourceMapCommand.js";
 import { PrivateRuntimeRootUnavailableError } from "../../../src/process/PrivateRuntimeRootUnavailableError.js";
 
 it.each([false, true])(
@@ -8,16 +11,24 @@ it.each([false, true])(
   async (retryable) => {
     const reason = "Native runtime self-test failed with a sharing violation";
     let launches = 0;
-    const result = await runSourceMapCommand("{}", "/selected.map", undefined, {
-      prepareOwnership: async () => {},
-      createRuntime: async () => {
-        throw new PrivateRuntimeRootUnavailableError(reason, { retryable });
+    const retainedCleanup: SourceMapCleanupRetention = {};
+    const result = await runSourceMapCommand(
+      "{}",
+      "/selected.map",
+      undefined,
+      {
+        prepareOwnership: async () => {},
+        createRuntime: async () => {
+          throw new PrivateRuntimeRootUnavailableError(reason, { retryable });
+        },
+        launcher: async () => {
+          launches += 1;
+          throw new Error("A refused runtime must not launch a codec");
+        },
       },
-      launcher: async () => {
-        launches += 1;
-        throw new Error("A refused runtime must not launch a codec");
-      },
-    });
+      retainedCleanup,
+    );
+    expect(retainedCleanup.owner).toBeUndefined();
     expect(launches).toBe(0);
     if (result.ok) throw new Error("Unavailable runtime must refuse decoding");
     expect(projectAnalysisError(result.error)).toMatchObject({