[buildkite] Fix backport PR pipeline generation (elastic#100427)

(cherry picked from commit f4d53bc)
brianseeders · Oct 6, 2023 · a45cb6b · a45cb6b
1 parent 360aed6
commit a45cb6b
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/.buildkite/scripts/pull-request/pipeline.ts b/.buildkite/scripts/pull-request/pipeline.ts
@@ -116,7 +116,10 @@ export const generatePipelines = (
     .filter((x) => x);
 
   if (!changedFiles?.length) {
-    const mergeBase = execSync(`git merge-base ${process.env["GITHUB_PR_TARGET_BRANCH"]} HEAD`, { cwd: PROJECT_ROOT })
+    const mergeBase = execSync(
+      `git fetch origin ${process.env["GITHUB_PR_TARGET_BRANCH"]}; git merge-base origin/${process.env["GITHUB_PR_TARGET_BRANCH"]} HEAD`,
+      { cwd: PROJECT_ROOT }
+    )
       .toString()
       .trim();