diff --git a/apps/cli/tests/profiles/sdk/plugin-manager.expected.e2e.ts b/apps/cli/tests/profiles/sdk/plugin-manager.expected.e2e.ts
index 494702c930..e27881ded0 100644
--- a/apps/cli/tests/profiles/sdk/plugin-manager.expected.e2e.ts
+++ b/apps/cli/tests/profiles/sdk/plugin-manager.expected.e2e.ts
@@ -155,8 +155,17 @@ it.for(['unavailable', 'approved', 'missing-pnpm'] as const)('reports the %s plu
     const result = JSON.stringify(requests.at(-1)?.messages)
     if (scenario === 'unavailable') expect(result).toContain('unavailable')
     else if (scenario === 'missing-pnpm') {
-      expect(result).toContain('ENOENT')
-      expect(result).toContain('operation-error')
+      const messages = requests.at(-1)!.messages as { content: { type: string; content?: { text: string }[] }[] }[]
+      const toolResult = messages.flatMap(message => message.content).findLast(block => block.type === 'tool_result')
+      const failure = z.object({
+        changed: z.literal(false), application: z.literal('failed'),
+        packageResult: z.object({ exitCode: z.number(), output: z.string().min(1) }),
+        error: z.object({ code: z.literal('operation-error'), diagnostic: z.string().min(1) }),
+      }).parse(JSON.parse(toolResult!.content![0]!.text))
+      // cmd.exe reports 1 for a missing command; POSIX spawn reports 127.
+      expect(failure.packageResult.exitCode).toBe(process.platform === 'win32' ? 1 : 127)
+      expect(failure.error.diagnostic).toContain('pnpm')
+      expect(failure.packageResult.output).toContain(failure.error.diagnostic)
     } else { expect(approvals).toBe(1); expect(result).toContain('entries') }
     const manifest = JSON.parse(await readFile(join(root, 'home/profiles/sdk/package.json'), 'utf8')) as { dependencies: object }
     expect(Object.keys(manifest.dependencies ?? {})).toEqual([])
diff --git a/scripts/smoke-python-runtime.py b/scripts/smoke-python-runtime.py
index 6819d780b3..baf65a9760 100644
--- a/scripts/smoke-python-runtime.py
+++ b/scripts/smoke-python-runtime.py
@@ -383,7 +383,13 @@ def completion_chunks(body: dict[str, object]) -> list[dict[str, object]]:
             outcome = json.loads(tool_text)
             if outcome.get("changed") or outcome.get("application") != "failed":
                 raise AssertionError(f"package operation unexpectedly succeeded without pnpm: {outcome}")
-            if outcome.get("packageResult", {}).get("exitCode") != 127 or "ENOENT" not in tool_text:
+            package = outcome.get("packageResult", {})
+            error = outcome.get("error", {})
+            diagnostic = error.get("diagnostic", "")
+            # cmd.exe reports 1 for a missing command; POSIX spawn reports 127.
+            if (package.get("exitCode") != (1 if IS_WINDOWS else 127)
+                    or error.get("code") != "operation-error" or "pnpm" not in diagnostic
+                    or diagnostic not in package.get("output", "")):
                 raise AssertionError(f"missing pnpm diagnostic was not preserved: {outcome}")
             return text_chunks(EXPECTED_TEXT)
         if tool_name == "load_workspace_dependencies":