[CI] Isolate CUDA coredump dir per run to fix tracker mis-attribution (#27344)

.github/actions/upload-cuda-coredumps/action.yml

@@ -29,7 +29,23 @@ runs:
       id: check
       shell: bash
       run: |
-        dir="${SGLANG_CUDA_COREDUMP_DIR:-/tmp/sglang_cuda_coredumps}"
+        # Mirror get_dump_dir() in python/sglang/srt/debug_utils/cuda_coredump.py:
+        # explicit override > per-job RUNNER_TEMP > /tmp default, then a
+        # per-(run, attempt) subdir so dumps are never mis-attributed across CI
+        # jobs that share a self-hosted runner's filesystem.
+        if [ -n "$SGLANG_CUDA_COREDUMP_DIR" ]; then
+          base="$SGLANG_CUDA_COREDUMP_DIR"
+        elif [ -n "$RUNNER_TEMP" ]; then
+          base="$RUNNER_TEMP/sglang_cuda_coredumps"
+        else
+          base="/tmp/sglang_cuda_coredumps"
+        fi
+        if [ -n "$GITHUB_RUN_ID" ]; then
+          dir="$base/${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT:-1}"
+        else
+          dir="$base"
+        fi
+        echo "dump_dir=$dir" >> "$GITHUB_OUTPUT"
         if [ -d "$dir" ] && [ -n "$(ls -A "$dir" 2>/dev/null)" ]; then
           echo "has_dumps=true" >> "$GITHUB_OUTPUT"
         else
@@ -41,7 +57,7 @@ runs:
       uses: actions/upload-artifact@v4
       with:
         name: cuda-coredumps-${{ github.job }}${{ inputs.artifact-suffix && format('-{0}', inputs.artifact-suffix) }}
-        path: ${{ env.SGLANG_CUDA_COREDUMP_DIR || '/tmp/sglang_cuda_coredumps' }}/
+        path: ${{ steps.check.outputs.dump_dir }}/
         retention-days: ${{ inputs.retention-days }}
 
     - name: Signal coredump to tracker issue
@@ -82,4 +98,4 @@ runs:
 
     - name: Cleanup CUDA coredumps
       shell: bash
-      run: rm -rf "${{ env.SGLANG_CUDA_COREDUMP_DIR || '/tmp/sglang_cuda_coredumps' }}"
+      run: rm -rf "${{ steps.check.outputs.dump_dir }}"