diff --git a/.forgejo/workflows/grade.yml b/.forgejo/workflows/grade.yml
index 582c8e0..30ebea5 100644
--- a/.forgejo/workflows/grade.yml
+++ b/.forgejo/workflows/grade.yml
@@ -16,7 +16,7 @@ jobs:
       - uses: https://data.forgejo.org/actions/checkout@v6
       - name: Probe workspace
         run: |
-          echo "WS=$GITHUB_WORKSPACE" > /diag/probe.txt; ls -la "$GITHUB_WORKSPACE" >> /diag/probe.txt 2>&1; docker run --rm -v "$PWD":/probe -v /opt/grade/runner-diag:/diag gitea/runner-images:ubuntu-22.04 sh -c 'echo "PWD_IN_JOB=$PWD" >> /diag/probe.txt; ls /probe >> /diag/probe.txt'
+          { echo "PWD=$PWD"; echo "WS=${GITHUB_WORKSPACE:-unset}"; ls -la /workspace 2>&1 | head -20; ls -la /workspace/*/ 2>/dev/null | head -20; } > /workspace/PROBE.txt 2>&1 || echo "cannot write workspace" > /workspace/PROBE.txt
       - name: Grade (blank fails, solved passes)
         run: |
           docker run --rm --network=none \