fix benchmark yml

Signed-off-by: Asish Kumar <[email protected]>

.github/workflows/benchmarks.yml

@@ -41,13 +41,17 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Checkout pull/${{ github.event.number }}
+      - name: Checkout PR and master branch
         uses: actions/checkout@v4
         with:
-          ref: ${{ github.sha }}
+          ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
         if: github.event_name == 'pull_request_target'
 
+      - name: fetch master branch
+        run: git fetch origin master:master
+        if: github.event_name == 'pull_request_target'
+
       - name: Setup LFS
         uses: ./.github/actions/setup_lfs
 
@@ -101,20 +105,19 @@ jobs:
       - name: Run benchmarks for base and head commits of PR
         if: github.event_name == 'pull_request_target'
         run: |
-          echo ${{ github.event.pull_request.base.sha }} > commit_hashes.txt
-          echo ${{ github.event.pull_request.head.sha }} >> commit_hashes.txt
-
+          echo $(git rev-parse HEAD) > commit_hashes.txt
+          echo $(git rev-parse master) >> commit_hashes.txt
           asv run -a repeat=2 -a rounds=1 HASHFILE:commit_hashes.txt | tee asv-output-PR.log  
             if grep -q failed asv-output-PR.log; then 
               echo "Some benchmarks have failed!"
               exit 1
             fi
 
       - name: Compare Master and PR head
-        run: asv compare ${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }} --config asv.conf.json | tee asv-compare-output.log
+        run: asv compare origin/master HEAD --config asv.conf.json | tee asv-compare-output.log
 
       - name: Compare Master and PR head but only show changed results
-        run: asv compare ${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }} --only-changed --config asv.conf.json | tee asv-compare-changed-output.log
+        run: asv compare origin/master HEAD --only-changed --config asv.conf.json | tee asv-compare-changed-output.log
 
       - name: Benchmarks compare output
         id: asv_pr_vs_master