[llvm-branch-commits] [llvm] release/21.x: [Github] Only look at previous commit for MacOS Premerge (#164483) (PR #164497)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/164497

Backport 288ef04d2f19c5b0e4ce3cae450c63a365ab11e9

Requested by: @boomanaiden154

>From 5bada6f8351ec0e35301e9d9722479dad83c089c Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Tue, 21 Oct 2025 14:04:03 -0700
Subject: [PATCH] [Github] Only look at previous commit for MacOS Premerge
 (#164483)

Otherwise we're looking for a commit that does not exist given the fetch
depth.

Fixes #164430.

(cherry picked from commit 288ef04d2f19c5b0e4ce3cae450c63a365ab11e9)
---
 .github/workflows/premerge.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/premerge.yaml b/.github/workflows/premerge.yaml
index d0518fa6879e2..8594e1e91ee99 100644
--- a/.github/workflows/premerge.yaml
+++ b/.github/workflows/premerge.yaml
@@ -149,7 +149,7 @@ jobs:
         uses: llvm/actions/install-ninja at main
       - name: Build and Test
         run: |
-          source <(git diff --name-only HEAD~2..HEAD | python3 .ci/compute_projects.py)
+          source <(git diff --name-only HEAD~1...HEAD | python3 .ci/compute_projects.py)
 
           if [[ "${projects_to_build}" == "" ]]; then
             echo "No projects to build"