From 0dfb04ebe36362fd3821aeddd88e3dbe8384c2ec Mon Sep 17 00:00:00 2001
From: Ian Clanton-Thuon <iclanton@users.noreply.github.com>
Date: Sat, 30 Aug 2025 21:34:22 -0400
Subject: [PATCH 1/2] Fix test flakiness in node-core-library.

---
 .../node-core-library/fix-tests_2025-08-31-01-31.json | 11 +++++++++++
 .../node-core-library/src/test/FileSystem.test.ts     |  3 +--
 2 files changed, 12 insertions(+), 2 deletions(-)
 create mode 100644 common/changes/@rushstack/node-core-library/fix-tests_2025-08-31-01-31.json

diff --git a/common/changes/@rushstack/node-core-library/fix-tests_2025-08-31-01-31.json b/common/changes/@rushstack/node-core-library/fix-tests_2025-08-31-01-31.json
new file mode 100644
index 00000000000..db57b2feb86
--- /dev/null
+++ b/common/changes/@rushstack/node-core-library/fix-tests_2025-08-31-01-31.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "",
+      "type": "none",
+      "packageName": "@rushstack/node-core-library"
+    }
+  ],
+  "packageName": "@rushstack/node-core-library",
+  "email": "iclanton@users.noreply.github.com"
+}
\ No newline at end of file
diff --git a/libraries/node-core-library/src/test/FileSystem.test.ts b/libraries/node-core-library/src/test/FileSystem.test.ts
index 0712f630c38..05e257d4917 100644
--- a/libraries/node-core-library/src/test/FileSystem.test.ts
+++ b/libraries/node-core-library/src/test/FileSystem.test.ts
@@ -43,10 +43,9 @@ describe(FileSystem.name, () => {
     });
 
     test('Should return true for an error on a file descriptor call', () => {
-      const buffer: Buffer = Buffer.allocUnsafeSlow(1024);
       expect.assertions(1);
       try {
-        fs.readSync(11, buffer, 0, buffer.length, -1);
+        fs.readFileSync(`${__dirname}/nonexistent.txt`);
       } catch (error) {
         expect(FileSystem.isErrnoException(error)).toBe(true);
       }

From dfc26f22496d210fddcaedf9068142c9114cdced Mon Sep 17 00:00:00 2001
From: Ian Clanton-Thuon <iclanton@users.noreply.github.com>
Date: Sat, 30 Aug 2025 22:01:26 -0400
Subject: [PATCH 2/2] Fix some test flakiness in rush-lib.

---
 .../api-extractor-test-05/dist/tsdoc-metadata.json     |  2 +-
 .../@microsoft/rush/fix-tests_2025-08-31-02-01.json    | 10 ++++++++++
 .../src/cli/test/RushCommandLineParser.test.ts         |  4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 common/changes/@microsoft/rush/fix-tests_2025-08-31-02-01.json

diff --git a/build-tests/api-extractor-test-05/dist/tsdoc-metadata.json b/build-tests/api-extractor-test-05/dist/tsdoc-metadata.json
index 89625ac60e4..5b39d9101b7 100644
--- a/build-tests/api-extractor-test-05/dist/tsdoc-metadata.json
+++ b/build-tests/api-extractor-test-05/dist/tsdoc-metadata.json
@@ -5,7 +5,7 @@
   "toolPackages": [
     {
       "packageName": "@microsoft/api-extractor",
-      "packageVersion": "7.52.8"
+      "packageVersion": "7.52.11"
     }
   ]
 }
diff --git a/common/changes/@microsoft/rush/fix-tests_2025-08-31-02-01.json b/common/changes/@microsoft/rush/fix-tests_2025-08-31-02-01.json
new file mode 100644
index 00000000000..bd7ff97cb34
--- /dev/null
+++ b/common/changes/@microsoft/rush/fix-tests_2025-08-31-02-01.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@microsoft/rush"
+}
\ No newline at end of file
diff --git a/libraries/rush-lib/src/cli/test/RushCommandLineParser.test.ts b/libraries/rush-lib/src/cli/test/RushCommandLineParser.test.ts
index a8122091dd1..02da1daeac7 100644
--- a/libraries/rush-lib/src/cli/test/RushCommandLineParser.test.ts
+++ b/libraries/rush-lib/src/cli/test/RushCommandLineParser.test.ts
@@ -47,6 +47,10 @@ describe('RushCommandLineParser', () => {
     afterEach(() => {
       jest.clearAllMocks();
       EnvironmentConfiguration.reset();
+      jest
+        .spyOn(EnvironmentConfiguration, 'buildCacheOverrideJsonFilePath', 'get')
+        .mockReturnValue(undefined);
+      jest.spyOn(EnvironmentConfiguration, 'buildCacheOverrideJson', 'get').mockReturnValue(undefined);
     });
 
     describe('in basic repo', () => {