From 836f86c04c8754ef9ee4b87f01ed758d4361b2c9 Mon Sep 17 00:00:00 2001
From: Alex Szabo <alex.szabo@elastic.co>
Date: Fri, 11 Sep 2026 16:34:57 +0200
Subject: [PATCH] [CI] Fix Quick-checks flakiness: force unused_deps to run
 sequentially (#290536)

## Summary
This pull request updates the quick checks pipeline to better handle
checks that require a stable workspace, ensuring they run in the correct
order and with appropriate isolation. The main changes involve
introducing a new `requiresStableWorkspace` property, updating the
partitioning logic for check execution, and adjusting the order of
checks in the configuration file.

(cherry picked from commit 7135bd59ca3cb8f5c1b8cfaa042c38af2eda647a)
---
 .buildkite/scripts/steps/checks/quick_checks.json |  5 +++--
 src/dev/run_quick_checks.ts                       | 12 ++++++------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/.buildkite/scripts/steps/checks/quick_checks.json b/.buildkite/scripts/steps/checks/quick_checks.json
index f96bde548761a..d829290a51a07 100644
--- a/.buildkite/scripts/steps/checks/quick_checks.json
+++ b/.buildkite/scripts/steps/checks/quick_checks.json
@@ -101,9 +101,10 @@
     "mayChangeFiles": true
   },
   {
-    "script": ".buildkite/scripts/steps/checks/unused_deps.sh"
+    "script": ".buildkite/scripts/steps/checks/unused_deps.sh",
+    "requiresStableWorkspace": true
   },
   {
     "script": ".buildkite/scripts/steps/checks/jest_negative.sh"
   }
-]
\ No newline at end of file
+]
diff --git a/src/dev/run_quick_checks.ts b/src/dev/run_quick_checks.ts
index a2291171e64cb..cc8f355ae023c 100644
--- a/src/dev/run_quick_checks.ts
+++ b/src/dev/run_quick_checks.ts
@@ -27,6 +27,7 @@ const MAX_ANNOTATION_OUTPUT_LINES = 50;
 interface QuickCheck {
   script: string;
   mayChangeFiles?: boolean;
+  requiresStableWorkspace?: boolean;
   // Additional properties can be added here in the future
 }
 
@@ -74,20 +75,19 @@ void run(async ({ log, flagsReader }) => {
     checks: flagsReader.string('checks'),
   });
 
-  // Partition checks based on mayChangeFiles flag
-  const fileChangingChecks = checksToRun
-    .filter((check) => check.mayChangeFiles)
+  const workspaceExclusiveChecks = checksToRun
+    .filter((check) => check.mayChangeFiles || check.requiresStableWorkspace)
     .map((check) => (isAbsolute(check.script) ? check.script : join(REPO_ROOT, check.script)));
 
   const regularChecks = checksToRun
-    .filter((check) => !check.mayChangeFiles)
+    .filter((check) => !check.mayChangeFiles && !check.requiresStableWorkspace)
     .map((check) => (isAbsolute(check.script) ? check.script : join(REPO_ROOT, check.script)));
 
   logger.write(
-    `--- Running ${checksToRun.length} checks (${fileChangingChecks.length} file-changing with parallelism=1, ${regularChecks.length} regular with parallelism=${MAX_PARALLELISM})...`
+    `--- Running ${checksToRun.length} checks (${workspaceExclusiveChecks.length} workspace-exclusive with parallelism=1, ${regularChecks.length} regular with parallelism=${MAX_PARALLELISM})...`
   );
   const startTime = Date.now();
-  const results = await runPartitionedChecks(fileChangingChecks, regularChecks);
+  const results = await runPartitionedChecks(workspaceExclusiveChecks, regularChecks);
 
   logger.write('--- All checks finished.');
   printResults(startTime, results);